One more vote for the dealer who did it in house. In your case if you go with the outside company get OEM or Pilkington glass and check their work on the rain sensor. What are they charging you?
08 E90 | Jet Black / Black | 6MT
Mods: RAC RG63 w/ Pirelli Corsa 255F/285R | Akrapovic Evo Exhaust | OEM Blacklines
Winter Setup: OEM 18s w/ Nokian Hakkapeliita R 245/40-18