What's a good glue to use on plastic? I know plastic can be difficult or impossible to glue but I'm just looking for something temporary. The end caps covering the factory roof rack on my suv are broken off. The person who installed the Thule rack on the factory rack attached it too tight and too close to the ends which pinched the end caps and caused them to break off. They are currenly being held on with electrical tape and tie wraps. I'm trying to put off buying a new set for as long as I can since it won't be cheap.

Thanks,
Dana