I'm in the process of buying a 2018 ST2 with 14k miles on it, and the dealership is asking 22k out the door, won't budge. I can't find anything wrong with it, but I'm taking it to a mechanic to make sure. Is this a decent price or am I overpaying? Any advice on what to look for to make sure it's hasn't been messed with? Only thing I can see is a custom exhaust.