in april of last year I went to AutoZone and bought five 10mm sockets, went to a tool show later in the year and bought two metric socket sets, and during that time had a friend give me a complete set of metric wrenches... took me over an hour to find a 10mm Wednesday.
I remember working on my 91 Grand Am (*cough* pos) and just like the civic EVERYTHING was 10mm or 12mm.
One day hundreds of years from now somebody will stumble across at least a dozen 10mm sockets and probably six 3/8" drive ratchets in the back yard from the last five years of work I've done on cars