Where to find rust on miatas

I was going to look at a "project" Miata tomorrow. From talking to the owner, it sounds rough (It would be winter project)

Where are to most common places to look for rust? What spots are the most difficult to fix?

I am going to look for a buyers guide but if anyone has a good link. please post it.

I know the rear window is torn. I am sure some water got in there .

Also, what is considered high mileage? It has 175K. Is it past it's limit?

Check anywhere, but definitely check the rear rocker panel in front of the rear wheels (worse if the roof drains were clogged) and the top of the B post.

GRM published a buyer's guide a few years ago. The sill in front of the rear wheels is the worst spot by far.

I am pretty sure there is rust on the rocker in front of the rear wheel. Are the rockers tough to replace (compared to other cars) I can do some welding but not sure I want to get into structural work.

check the battery area for any acid that may have spilled. Some people are to cheap to put the correct sealed bettery in and use a standard one.

kaw550 wrote: I am pretty sure there is rust on the rocker in front of the rear wheel. Are the rockers tough to replace (compared to other cars) I can do some welding but not sure I want to get into structural work.

Email Willy about the patch panels he sells or check out the eBay store.

If the car's been parked outside on a slope (front to back), I believe the bottom of the frame rails at the ends can rot. Note: this is based upon a sample size of one. I've heard of windshield frames rotting, but that should be pretty obvious.

It can't hurt to check under the floor carpet (if possible). At least look for signs of water getting into the interior (water stained carpets, mold, etc.).

The only things that cause rust in miata are clogged drain line or a bad rain rail. I bought one car that actually sloshed after a rain until I pried the drain holes open. Not really sure how they got closed up. Take a long steel rod or clothes hanger and auger out the drain holes from the top. You might be able to blow air thru them but take a look at the bottom of the drains too. A split rain rail is much harder to correct.

You don't need to park it on a slope to rot out the back of those sills. I've seen the frame rails get pretty thin from rust, but that's an easy fix with a set of bolt-on reinforcements.