Not sure where your at, but if you're facing freezing temps you might already know this... about twice per winter I spray a rag with a silicone lubricant and wipe down all the rubber seals on the car doors & trunks. This prevents the rubber from freezing onto the vehicle itself when things get cold. I do this once in the fall, and usually once more mid-winter. The silicone 'conditions' the rubber, and helps discourage dampness from causing the rubber to freeze onto other surfaces.
I don't have a slide on our TT, but suspect in theory, the same practice might be wise as it would protect the rubber and possibly help it last a few extra years.....
3 kids and Buddy the Dog;)
2010 JayFeather 23K
05 GMC Envoy XL