Originally Posted by SlickShift
The bolts/studs are 8mm on my 3/09 build 1er. RealOEM might say 5mm, but they're 8mm on both the old PN light and the replacement light. It will help with a deep socket, but I did not find it necessary.
Nuts and bolts are specified by thread size (and pitch), length and head type, so the thread is 5mm (as specified in RealOEM), the socket size required for the nut is 8mm.