Seems if you keep it on the roof always, shouldn't you tire shine it everyone in awhile? It sits in the sun, all day, never gets used, can't be good for it.
That's why I put "Aerospace Protectant 303" on my spare on the roof, has SPF 40. and I applied it generously. It's not greasy/oily or anything, no residue at all.
VX KAT
....the adventure BEGINS ANEW! ...2015...... Remember that life is not measured in the breaths you take, but rather in the moments that take your breath away.