I don't know if this is a frugal tip, but once you pay off your car, continue to make car payments to a savings account. This way you may buy your next car in CASH!
If the car you paid off does not make it until you have enough for another one, you will have bargaining power and a lesser car payment. And, we follow what Dave says - No Fleeces and No new cars (they are holes in the road for money).
>>No new cars (they are holes in the road for money).<<
Although I generally agree with this, when I bought my Scion xB I noticed that all the used ones were only one or two thousand less than a new one. So I bought a new one. I got exactly what I wanted with a full warranty. In that case it was definitely worth it. But other than that, I agree.