[Porsche virgin]

I've been looking at cars (as my wife will tell you I do all the time, regardless of whether I'm in the market or not), and it seems like the high mileage cars (70k+) are all at no-name used car dealers.

When new car dealers get high-mileage cars as a trade in, do they immediately ship them off to auction? Is this where the used-car lots are getting these cars?

The reason I ask is because I put maybe 5k on my car per year, and there is no reason why I couldn't buy a high-mileage, well-built car and use it for years.

Thanks!