I tried a full cover once; never again as, yes, it marked the paintwork.
For a few years, I have been using a small sized Halfords car cap; its actually oversized for the car. You can sort of lash it down around the corners of the bumpers and wheels, and it’ll stay on even in the most heavy of gales. Its not waterproof (water resistant), but will stop that heavy build up of water that might result in a leak into the car.
The wiper blades hold the front down with a strap that goes forwards and under the front bumper. There are pockets for the mirrors that hold it down at the sides and at the rear is another strap. Very well made and stays where it should.