I couldnt find metric rivets up here even if i offered my first born. Up here we guesstimate by eyeing up rivets and hope for the best. HMMMp,and i thought Canaduh was using metric system. Bump for motorgeekiness,lol!
So, for anyone interested, I think I got pretty damn close to what the matches factory rivets. I was somewhat correct in my decoding, but the US/Standard coding system is a little different.
The long molding along the sides, exterior B-pillar, and clips that run up the A-pillar (for the windshield/exterior trim) uses Audi part number N90576301 or the metric rivet code of A4x9x8x1.2. This equates to an AB5-3 (Marson, 3/16").
The small clips that are at the top of run the A-pillar (for the windshield/exterior trim) uses Audi part number N90437601 or the metric rivet code of A3,2x8. This equates to an AB4-3A (Marson, 1/8"-3/16"). Their hole size is 1/8" and the grip range (body length) appears to be good enough to grab both the thin clip and the sheet metal.
I spent like ten minutes picking the guy at the fastener warehouse's brain, looking at the different sizes, and those dudes shoot metric to standard size match off the top of their head fast.
Now maybe thrifty geeks can skip the dealer when replacing their trim or when putting their car together from scratch like I (idiot)!