Ok heres one way for you to decide what you want to do.

The new EVO= Spending more money on monthly payments with less money to mess with the car/ New car with new car warranty/ Less problems with it breaking down because of random little shit (unless you start modding heavily)

The Old Teg= More money to spend to mod and customize however/ Old car with old car problems/ Might breakdown occasional cuz, well its old.

IMO go with the teg you got less of a commitment in terms of money to put towards it. Also the EVO will lose value the longer you own it and the value of the teggy will go up as you slowly mod it.

Good luck.