stealing of these mirrors is very common down here. you will see base tahoes,silverado's with signal mirrors down here. and for what? they sell them for like 60.00 for the pair.damm sucks. sorry for ranting its just they are so expensive to replace. they sell a ring molding that i beleive is made in Mexico that goes around the mirror. it will prevent the mirror coming out.it goes on the outer part and over the housing of mirror. they sell them for 119.00 for the pair pricy BUt it will work and it looks subtle so you wouldnt really see it cus its black.
Link? would like to know more.