Tip: Should you buy a new or used car in South Dakota? Great Question, think about this for a moment. If you buy a brand new car, the value of that vehicle drops amlost immediately as you drive it off the new car lot. Now, a lease trade in vehicle, with less than 25,000 miles and less than 2 years old has already taken that 20% depreciation loss in value. You still get a pretty new vehicle and a factory warranty for at least 20% and sometimes 30% off new car price.