Make sure it's OEM Glass..... if you have the rain sensor, make sure it is FLUSH with the inside of the glass or it will bubble.
Sometimes the windshield wipers get messed up but that is an easy adjustment.
oh yeah....make sure it's OEM Glass.... and OEM seals, upper and lower.
2006 Lotus Elise SC
2008 AW E92 M3 6MT - Sold
2004 AP2 S2000 - Sold