Grippifying Thule load bar end caps

The end caps on my Thule load bars on two vehicles fall out from time to time, most especially in a car wash. They need to fit tighter somehow.

I don’t want to glue them in because I might want to remove them if I ever want to remove the bars from the towers.

Any idea of some sort of “grippifying” substance to put or paint on the end caps?

Maybe a really weak glue would work – one that would shear off with a bang on the end cap – but I don’t know what that would be.

Gasket Cement
There are a bunch of different kinds, but my first choice would be the non-hardening variety of “Form-a-Gasket”. Should do the trick.

not supposed to leave on
If using a drive through car wash you void all warranty and risk serious damage leaving any car rack on although people do it. If you lose the end caps at a do-it-yourself car wash then remove before hand and replace after like I do.

Any drive through car wash attendant will tell tales of Thule/Yakima parts found all over the place each week. So take em off!

Please forget car washes
It’s an irrelevant tangent that I needn’t have mentioned.

GBG, thanks for the gasket cement suggestion.

Black electricians tape
easy to take off, but can’t really tell that it’s on there either.

A little dab of silicone … EZ to grab
and pull off if / when you want.