Buying a new car with the wife and I can't decide whether to trade in her impractical but super fun '07 Mini Cooper S convertible w/50,000 miles, or trade in my conservative but comfortable '07 Toyota Avalon Limited with 105,000 miles. The Avalon is worth $600 more on the trade in. Given the mileage, which car would you hold on to? I'll end up driving whichever vehicle we don't trade in. Flipping a coin hasn't helped so far!