well I'd say looks good, way better then my first supra is/did. As for the rust definitely give it a thorough check through look under the car and everything you can never be to careful, as for treating rust you should take a wire brush or wheel to it if its just surface rust or if its rusted through you'll have to cut it out and then after all that's done prime it immediately, if you haven't done body work before I highly suggest taking it to a professional for the repair. But to me it look extremely clean, and for the age you cant ask much more of it. Remember to take your time seeing as your the buyer, look for oil leaks and make sure all your the vents work etc.. and power options if it has them. As for the mk3s non turbo engines i have no clue, Im still really new to the supra as well. I've only had mine for 4 months (84 mk2) and barely driven it cuz it needs a lot of work the previous owners were terrible (didn't ever change the oil since they bought it). puts my supra to shame that one, I'd try and get him down by $400 though if you can then it'd be a super good deal. I bought mine for $800 barely running and paints garbage plus it has a lot of electrical issues. Anyways I'm rambling hope I was of some help! hope you decide to join our pack, your always welcome! keep us posted
