I'm getting ready to install 20mm clamps on my 02. Are there any things to watch for when the shop presses my old stem into the new clamp? Can it be pressed in too far or not far enough? Also, has anyone tried an 03 cdi unit on an 02 either with or without an 03 cam? Is it a better mod than the cam alone? And, why does it always rain after I wash my car?