I want to get a blind spot monitor for my vehicle. It was a mistake not to get it as an option when i bought it. I see some universal BSM devices in Amazon and ebay but the reviews and few purchases make me question the product quality. Also, will installing this void my warranty? I have the Bumper to Bumper extended warranty and am worried that getting it installed may void my warranty. Do I need to consult my dealer before I go ahead with the installation?