The first thing I learned is that the current A6 has little "blocks" that create a self aligning install. The installers told me that the older models do not have this. It is pretty cool. The most important thing I learned is that despite the "blocks" being there, there is still a little up/down wiggle room. They had to push up my new glass towards the roof (about 1/8th of an inch) so the gap between the glass and the roof body was the same as the factory installed piece. This is not a seal issue, just my ****-retentive nature wanting it placed exactly as it was the first time. You know, not having the hole for the VIN # lined up EXACTLY would have sent me to therapy! :-) (I probably need some). The new windshield, which is Audi glass ordered by my dealer has no waves in it when looked through it towards the side, unlike the original piece. That makes me happy, even though it never bothered me. The other interesting thing I learned is that the windshield for the Avants is different from that of the sedans. The glass shop learned this through a "trial and error event". It was not their fault apparantly. Audi had an incomplete/incorrect code which resulted in a sedan windshield being shipped instead of an Avant windshield. If you have your windshield replaced, make sure the installers double-check the numbers AND measure the new glass first before they cut out the old windshield as my shop did.