I really tell people to hold on to there stuff, or factory stuff in case they evere want to sell the car. Most of the time you cant get your $$$ back to cover what youve got in the car so we put the factory stuff back on and people sell the aftermarket parts and can get more money for there parts. If you want to sell your pre i pay 35 dollars for them. Thats per cat or 70 for the two,.