From PM:
No, they don't pull off at all, once I added more tape as described in this thread.
They "tarnish" a little, but polish back up pretty easy. They also have some sharp edges that rub a little on the part of the handle that doesn't move. I think, if I were you, I would look into getting the OEM metal handles that are coming on the 2006 4runners. They could be too much money, but I sure would prefer the better "fit" of a one-piece handle. Mine feel slightly weird when you grab the handle.
Also, if you still want to go with the stick-on type, I'd probably try the other type......the non-JDM, non-JasonB type (good guy/seller, but I just don't love these handles). Maybe they'll fit a little better.
BTW, I couldn't ask for anything more looks wise out of these handle covers.