Hi Guys I just had the transmission fluid changed on my Beetle. Its a 2003 Turbo S 6 speed manual. I noticed that the next day the transmission fluid was leaking from the drain plug. Does the drain plug require to be replaced or can you simply buy a new o-ring? Also since my oil is gonna drain should I use the red-line MT-90 or OEM oil? I read many different opinions about this and im confused. Thanks.