I don't know if anyone here is familiar with the EZ-Pass system on the New York State Toll roads (and surrounding toll roads), but they use that stuff to stick a little (several oz maybe?) radio transmitter box onto the windshield so you can go through an automated toll lane at the toll booths.
I have had these things in my cars for almost 10 years now, and not once have I seen it fall off (plenty of pot holes in Upstate NY too). So, as long as the object isn't heavy (or in a servo's case try to exert a force while staying stationary) it should work out fine.