I do use tire covers. But not for the sun so much. On our Class C the rain, dew, AC drain water ect runs off the front and drips on the front wheels. It washes the grease out of the calapers and they freeze up. giving braking with just one front disk pad. I had to take them apart and fix them when we got it used. So I just cover them every time we are parked over night. I do use front and rear after being ask why just the front. Decided it was easier to just cover them all. But none of my friends use them. I do make money fixing their front calipers every few years so I think they are right.