Just tried it in my '04 WRX wagon. At about 72,000 mi. my 4th gear synchro was crunching like a bag of Doritos. I was sure I would have to just live with it or delve into a huge PITA tranny repair. I would never have believed a gear oil change would quiet things down in there, but I was wrong. Had to go to 5 stores around west Denver to find it all, but well worth it!
I was a bit freaked out when the Shockproof came out of the bottle Valium BLUE!