2003 Sable Common problems?

Hunting for a cheap reliable car that will mostly be used by my kids for high school, and ran across a 2003 Mercury Sable V6 with 95k miles on it, seller wants $3000. But I did haggle a bit and got them talked down to $2500. Anyway, I test drove it the other night, but haven't given it a good look over yet. Test drive seemed fine. New tires, it's in really good shape, seems to have been taken care of. Just curious what common issues/red flags to look for on these cars? Or if I should stay away from them.

It's really between this and a 2000 Chevy Malibu (V6) with 102k miles on it, for a much better price, $2000. Haven't test driven that one yet, will tonight. Thanks in advance for any input!

Also, I can only assume that this car is going to have the rear sag issue like most of them. I am going to go do a more thorough inspection today, but it certainly does seem like the rear is lower over the tires than it should be. I didn't look at them in person when I was there, but in the pictures, it is pretty much covering the top of the tire.

Can anyone also recommend a decent replacement strut/spring assembly?

I really don't want to get into having to replace the rear suspension on a car I'm just about to buy, but this one seems to be in particularly good shape otherwise, so I'm still considering it. But I will get a better look at it today. If the underside is terribly rusty, I won't even begin to want to touch the suspension lol.