I have them on both sides of my '04 coupe and like someone else said, they're the best investment you can make for the car. Installation takes about 10 minutes or less, depending on how adept you are with such things. I did use the black silicon caulk on the passenger side mirror, as that mirror projected outside the mirror shell. The driver's side did not so I havent bothered with the caulk on that side. They really do improve visibility and they are high quality optical glass -- not plastic or polished metal.