For three large car seats across, my Nissan Titan Crew Cab is great. I can't see fitting those car seats in anything smaller. My kids are about the same age spread. I moved the two oldest (my middle son is big for is age) into backless booster seats when in my 92' Galant VR4. They also fit my in-laws '03 Corolla and '04 Prius like that.
Yeah SUV's and Trucks don't work well in underground parking garages.
I just pulled out the tape measure. I have three cars with LATCH anchors. I think the overall width of the anchors from outside to outside is the real deciding factor. If anyone else wants to take a measure to their car (especially the full size Chrysler products or the Altimas mentioned) then I think it would be helpful.
2014 Cadillac CTS wagon - 39 inches.
2007 Toyota FJ Cruiser - 44 inches.
2007 Chevrolet Silverado crew cab - 50 inches.
Note these are not the seat widths, just the latch widths and show you that you'd have right about 11 more inches of space in the middle seat of the truck than the wagon.
Pull out your tape and help the guy out.
Our Volvo 850 fit three car seats across the back.It was tight and no fun getting the middle kid in but they fit. In that car they were all within punching distance of each other. But close enough that they could not get full swings in. But in the minivan they can kick each other in the back of the head so in a way its not better. (I have three boys)
I think the Accord 4cyl/5spd is a good one to check out. Should be somewhat sporty, and should fit.
There are very few cars that will truly fit three across. Our Dodge Ram Quad Cab does, for example, but even in that it's tight. I'll try to take a picture this weekend to illustrate...
Javelin wrote:
Mazda5 won't hold 3 across (or 3 car/booster seats, period). I just went through this in March and settled for the Saturn Vue. Ecotec 2.2L, 5-speed manual, 3 LATCH/tether anchors.
The Pontiac Grand Prix will do 3 across. Auto only, but factory supercharger cures a lot.
The Saturn VUE should be the official GRM SUV..
Vigo
PowerDork
5/9/14 2:24 p.m.
Woah woah woah. XJ Cherokee, buddy! How about official CUV? 
Dakota Crew Cab? Kinda modest in size as far as trucks go...
You aren't fitting three across in anything without three LATCH anchors, so find that list online (lunch break on cell phone or I'd link it) and start shopping. Think midsize/full size sedans, big trucks, and a surprisingly small selection of wagon/SUV/CUV. The Vue is the shortest physically in length iirc.
The five year old should be close to a belt positioning booster, yes? Mine were by that age. That means only two sets of latch anchors and a three point belt in the middle.
Hal
SuperDork
5/9/14 5:26 p.m.
A friend of mine just bought one of those 4 door Jeeps. They have the rear seat set up with a rear-facing seat in the middle and a booster with back on each side. Seems to work well for them.