my friends sprayed his stock lights on his 2002 2.5 rs, he put the spray right over the orange markers, and you could tell there was another color under it... he also did it outside where it was kind of dusty, so the job didnt come out that good... i think doing it over clears would be your best choice... but you can always do it to your stock ones now, and then if you dont like it buy clears and do it to them.
David