DUDE i would not even advise changing the STOP tail lights it drove me crazy i put them in the same day i had my HIDs done and i confused myself thought my HIDs wer messing up coz everytime i Breaked my sidelights would come on and i would have a warning light on and off EPC coz i completely forgot i put em in eventually i worked it out but its like ive searched everwer they wer ERROR free bulbs aswell soo lool

You need load resistors for them to work properly.
 
DUDE i would not even advise changing the STOP tail lights it drove me crazy i put them in the same day i had my HIDs done and i confused myself thought my HIDs wer messing up coz everytime i Breaked my sidelights would come on and i would have a warning light on and off EPC coz i completely forgot i put em in eventually i worked it out but its like ive searched everwer they wer ERROR free bulbs aswell soo lool

i had this and no one else had it, i got soo ticked off i put normal 501 bulbs back in, stopped the front brak lights so i was happy, not had any othere issues (bar shat looking side lights)
 
they will flash stupidly quick i think... i know they do on motor bikes any way