My 2000 Camry began its life as a rental car, until I got it in early 2004. It had ~42k miles on it (in four years!), came with a stack of receipts that were signed off on by a local Toyota Dealer's Head Mechanic, and even came with a sheet that was essentially a Summary of the car's life up to that point (had month/year it was made, which plant, all specs and options, and what surprised me most was it had things like Avg Trip Length, Longest Trip, Average MPG, Total Times Rented, Total Repairs - Mechanical, Total Repairs - Body, and like a dozen other things like those, apparently it was stored on computer and then printed out for car's sale).
If it hadn't of come with that, I would have been more hesitant, but combined with Carfax and service history, I knew: zero accidents, average rental period was 4 days and 342mi, its tires were only 199 miles old, it had the oil changed every 2950 miles with Mobil 1 Dino and "Toyota Premium Oil Filters", air filter replaced with OEM part every 6k miles, headlight bulbs replaced with Hella bulbs at 39.5k, then lastly belts, trans fluid, oil/filters, plugs, fuel filter, brake pads/fluid, and coolant changed at 41k, about 600mi prior to selling. It was a smaller chain, and they had like 20 Corollas, 20 Camrys, 15 Avalons, a mix of Toyota SUVs, and about 10-12 total of Lexus ES300/LS400 and lastly about 5-6 3rd Gen MR2s with one lone 90s SC400. They had some deal with the Toyota dealership where they buy exclusively and they get discount but have to service at dealership, because the invoice for my Camry's original sale was $4k less than a no-option base model yet it is an LE with in-dash CD player (Fujitsu-Ten, aka Eclipse) and a handful of other options.
I tried to get them to sell me the SC400 knowing I could turn it into one wicked luxury sports cruiser, but the owner said that when they retire it, he is going to keep it.
Anyway, point is, I got lucky I think in that I had full records and they are also all on the dealer's computer. Not to mention I got a 4yr old car with 42k miles (with all service for the next 30k aside from oil and filters done, and brand new Toyo tires) for $5k.
I still have it, too, and that car has been beaten on and at 191k miles or so, runs hard. The engine is sludgey, but it is a 5S-FE, that is what they do.
So, I have about 0.8qt MMO in the crank with some "whatever" oil, and after the MMO has steamed/evapped off, I will add a half-dose of Seafoam and drive 150mi then dump that nasty gunk.
I have a 5.1qt jug of 5w30 Pennzoil Platinum and MobilOne (me? Mobil 1? Surely it cannot be!) Extended Protection oil filter sitting here waiting to go in. After however long I feel like, I will dump it and gradually use stronger cleaners every other change while continuing to use Very strong cleaning-power synthetics (PP/PU, T6, RP maybe, etc) between cleaning cycles (during which, depending on what is called for, I intend to use T5 and/or Pennzoil conventional).
All in all, eight years, not a single breakdown, cheap to maintain, and still.running hard... If I had to do it again, I would've been more convincing about the SC400, lol, but I would not hesitate to do it again.
However, that was what I consider a very lucky score. I will not ever buy a former rental again, except perhaps for a kids-first-car or something and only if it passes MY inspection, my mechanic's inspection, and my friend-who-owns-his-own-body-shop inspection.