How many cars do you need to always have a working daily driver?

I had two old cars and decided that wasn't enough, so I bought another one and decided that 3 old cars wasn't that fun and sold the one that needed the most work with the intention of buying either a brand new car or a better used one. 

Now, new cars are 2+ years out or $10k over sticker price (and I have looked at everything I can think of and can't find one I don't dislike that isn't too expensive),

all the (older) used cars I liked are double the price of a running one from two years ago for one that I wouldn't even want to try to drive home, or gone in less than an hour of being posted for sale,

and of the two cars I have, one I am still driving daily but it needs a lot of work (some of which I am not even sure the parts still exist to fix), and I got stuck trying to change the engine mount on the other one and can't get it back together.

So, one 25 year old car with 500k miles on it definitely isn't enough, a single new car isn't enough (backordered parts and no loaner or rental cars mean you still need a backup and would be at least a year or two away from helping anything anyway), so I am curious what other people do? 

I've got 2 30+ year old cars for me and one newish car (bought in 2019) for the spouse.  WIth my old stuff one has excellent parts availability (Chevy truck) and the other doesnt (Infiniti G20) but that one shares enough parts with other cars (Nissan Sentra, 200SX, Altima etc..) that i can get most of the hard parts i need to keep it going.  Hopefully those two will last me until this car market madness ends (Knocks wood)

At least 7. 

For me, it's always been two. Thirty years of driving has proven that out. 

When one needs attention I can focus on it at a sedate pace without worry since I have the other to use.

That said, I am very, very obsessive about the work I do on them.I started out many years ago as an A&P which ingrained the principles of doing things correctly for maximum reliability. 

I suppose the numer for me is 2 as well. I typically have one daily driver and then my tow vehicle as a back up.

If you take very good care of them and do quality and complete repairs, one. 

I take reasonable care of them and mostly do quality repair work. I have been known to let broken vehicles stay broken until I have the time and urge to repair them. I have 3 personal vehicles as well as a company vehicle. One of my personal vehicles has been down since last fall with a spun rod bearing. It will probably be next fall before it makes it to the top of the repair list. 

Two?  A primary and a back-up.  As soon as the primary starts becoming one of my projects, it gets sold/traded in on something that I don't have to think about. While I have used some of my project cars as daily drivers, that is not their purpose. 

Currently: 2017 Grand Caravan is the primary and a 2006 MINI is the backup.  The latter also serves as a weekend toy and backup LBC when neither of the Triumphs is running (which is more often than I care to admit...). I would like to think that some day my Volvo can be a daily driver, but being realistic - probably not.  I totally see the current minivan getting replaced with an EV van at some point in the future. Hopefully, a manufacturer makes one before the GC starts being a project. If not, I'll likely end up with another used minivan.

Currently 3. 
 

2003 nissan pathfinder, (family offroad toy and fun cruiser), intake is off to access the deep doodoo in and behind the engine V. Been sitting like this for months now. 
 

e36. "Reliable" driving project. Still have a pile of parts to put on. 
 

Nissan frontier i have had for 23 years. Reliable despite all my inadvertant attempts to kill it via lack of maintenance. Needs a boatload of work but still can DD. 

I've been doing the routine of having one daily driver per driver in the household, plus one. The one has been the GMT400 that I've had since 2010. 

Since my son is now driving himself to school, I just added a 2008 civic for myself. 
 

Unfortunately, the truck is having a glitch right now. It has failed to start a couple of times, where I turn the key and get absolutely nothing. Unfortunately, I guess, it hasn't been repeatable. I've been planning to replace it soon, but prices are just ridiculous right now. I paid $6500 for the civic, which was a lot for a car worth $3500-4000 a year ago. 

I've also always had the strategy of a cheap, reliable daily plus whatever projects I wanted. I had friends in college that had projects for daily drivers, but I've always needed the separation to make owning either one enjoyable. Right now, that means a 2012 Mazda3 that runs great and will for a long time. That lets me have my track-oriented Miata, stock car, and as a bonus I don't have to kill myself buying gas to daily my truck. The Mazda3 is boring, but that's all I want it to be, and it does a great job.

One under warranty with a loaner car program. That's the daily driver. spent too many years working on multiple older cars just to make sure I could get to work. Not worth it.

If you keep buying the same model as your back-up car, chances are that you can always get one running.

Not actually sure how many I have registered/insured at the moment.

Four for 3 drivers. Spouse gets the best (2015), teen gets her choice (truck) and I get the 2 Jeeps to choose from. If one goes down, there's one spare usually. I could walk or bike to work if needed.

We need to trade off/upgrade but prices and availability are holding us back right now.

Also 4 projects that never move. Soon.

Right? Soon? 

One. Buy it well and maintain it.

Having more cars makes the maintenance of the One Reliable Car more difficult, and you're also more likely to have trouble with it sitting. My wife's WJ Jeep was her only car for years and was 100% reliable (other than a battery failure at about 15 years old, but batteries are a quick fix that can be done by a tow truck) that whole time. Now it's 22 years old and the only reliability problems it's having have been related to the fact that it's rarely getting used, such as a dead injector. Sure, it's needed other stuff like sunroof drains and brake jobs and a CV boot, but nothing that kept it from being driven on demand.

In reply to Keith Tanner :

The big one is if a car that needs to be reliable is going to sit alot, it still needs regular checks and maintenance.  And it needs a good environment to sit in.  Sitting outside or in a perpetually damp garage is a recipe for problems.  But sitting in a dehumidified garage (even better if it's heated in the winter) and on a battery tender when not being driven greatly reduces the problems from sitting (no sticky / rusty brakes, etc.).  My Jeep hardly gets driven these days, but pretty much any time I want to, I can walk out to the garage, check the fluids, turn the key and it'll run and drive exactly as it did the last time, even if it hasn't moved in 9 months.  Speaking of which, I do need to move some stuff and drive that thing.  Hasn't been out since last August...

One.

That works until you start to have problems with things like stale gasoline. See my note about the dead injector on the WJ in question. I've also had to clean injectors on a car that had been driven cross-country happily and then sat for a year inside a heated/air conditioned garage. It's also easy to overlook things like tires that are 15 years old when the car sits or when it's not used regularly.

With multiple cars, you're also more likely to put off maintenance and/or repairs on the daily driver because it just works. The project car with the bad transmission is more likely to get the attention.

(Total number of drivers in the family) + 1 = Number of vehicles required (assuming an old/aging fleet)

One more. 

AAZCD-Jon (Forum Supporter) said:

If you keep buying the same model as your back-up car, chances are that you can always get one running.

Not actually sure how many I have registered/insured at the moment.

That seems like a good idea, especially since waiting on tools/parts seems to be a big part of why one car isn't enough. The last 5 years or so it seems to take at least two weeks to get parts for any car over 10 years old.

I don't think I would enjoy having that many Boxsters though, I have had so much trouble just doing some basic maintenance on the one I bought a year ago that I haven't even driven it enough to need to put gas in it.  All that was really broken was the starter and thermostat (both of which I changed), but I tried to replace the motor mount and don't know how to finish the job, so it just sits there with a jack under the engine while I try to ignore it.

3-4.

Shockingly the entire fleet currently runs and is in a decent state of repair

This question feels like a personal attack.

Mndsm said:

At least 7. 

Heh...I have 7 right now and only one is reliable and inspected.

Will said:

This question feels like a personal attack.

Lol well I am definitely not asking for a friend, I figured I wouldn't be the only one here who has that issue.

ProDarwin said:

One.

This!  Buy a newer very reliable dependable daily driver.  It makes having hobby cars more feasible and a lot more fun.  My DD is serviced at the dealer according to it's schedule and all I do is insure and drive it.  I hobby on my hobby cars.