Re: Which vehicle? (3Series)
Least mileage and cleanest service record.
Everything else is the sizzle, the mileage and lack of major breakdowns is the stake.
2.5T was around forever, it will last longer than you would want it, if you would not treat the XC90 as the sport coupe.
Had 04 2.5T for 89K miles, lost in accident, insurance company totalled it due to the sucking used car market in CA.
Bought 05 V8 with all bells and whistles, including Nav, bi-xenons, custom 20" wheels with 53K miles for $16,500. You should bargain harder. I've got almost 15K for my car as a settlement from the insurance company (and this is -$500 of deductable).