tonight my friend was driving my 95 M6 z28 around and all of a sudden when he pulled up to a stop sign, we could not get the car in gear. we tried 1st through 6th and reverse and it would not go into any gear. this has never happened before. after like 30 seconds at a stop sign, it finally went into gear. could this be the clutch? tranny? i am wondering if he was riding the clutch on accident or something. i then got in the car and drove it around and the car seemed fine. suggestions would be great. also, has anyone used or heard anything about the seafoam for tranny's? or is this only for auto's? thanks