A few things you can do:
1. get the vin and check the carfax report
2. requested the seller if you can go to his insurnace agent to pull up the history thru his agent (the private seller would need to give his/her authorization to release the report to you)...shows accidents/speeding, etc since they have owned the car. - only possible when its a private auction...as no dealer would have that info.
3. take the car to an inspection shop to get it checked by them..(in houston, it costs you close to 60 bucks..i've heard other places it costs close to 125..so i don't know what the pricing is in Michigan
4. take it for a test drive - see if its something you love/like.
if all checks out...(its a toyota..it should..but you never know)...then buy the car!
As far as turbo'ing a 2zz engine??? You better do a lot of research on that PRIOR to your purchase. Cus' among my personal friends...on 2zz's, all i see are intake, exhausts..and lowering....nothign more...on 1zz engines...i see a whole lot more....so do your research PRIOR to your acquisition. and GOOD LUCK!