Hi Reg and Pat
We use a Protec caravan cover and we are now on my 4th winter with it. On our first use the sharp end of the front aluminium roof joint strip rubbed a hole. Cary repaired it with some of the spare material which Protec provided when we bought the cover.
Subsequently I rounded the ends of the roof strip a little with a file. I have a routine I follow before re-fitting the cover I gaffer tape foam pipe lagging (the long foam tubes with a centre hole, along the ends of the strip and down the wall a bit. The gaffer tape holds the foam securely but does not damage the 'van's paintwork when we remove it. We, also, secure pipe foam around the edge of the Status 530 aerial and the around the gas fire "chimney" with thick rubber bands. Our cover is "tailored" to our van so it does have "extra" to go over protrusions like the aerial and chimney. We, also, purchased the optional storm straps as we keep our 'van in a rather exposed position in the windy North West.
With these measures we have had no further problems of damage to 'van or cover in the last 3+ years. The cover is a bit of a pain to take on and off but it keeps the 'van beautifully dry and clean, especially the roof as we, too, store our 'van under trees.
Hope this helps.
Tim