Would a 16" spare fit on a 2006 Boxter?

 

16" sounds too small, not sure if it would clear the brakes, it won't on the S. I carried a 996/986 inflated spare in my cayman. That is 17". The total height is a tiny bit too short, but would work on the front if absolutely necessary (and the front could be moved to the back if the flat is in the rear).

 

FWIW, no need to reinvent the wheel if you are willing to spend some $$'s. Here is a nice "turnkey" solution:

http://www.suncoastparts.com/product...Code=987wheels

IIRC they are also a sponsor.