first of all , car cover is big source to create light swirls and secratches to car skins so many people avoid car covers but our problem is we are living in dusty enviornment and if we dont cover car than in few hours u will notice a layer of dust on whole of car and most people dry dust that layer which even more harmful for car skins compare to the loss by using car covers
we can minimize the risk by
a) use good quality car cover
b) car skin allways properly waxed ( as wet surface resisit to secratch compare to dry skin )
c) car cover inner layer should be clean ( i almost after every 2 weeks clean my car covers inner surface by moist microfiber )
d) allways clean car skin before putting car cover on it.
in pakistan we have following types of car covers easily avilable
1) basic textile cloth cover ( dark grey type )
very light weight and most economical but useless as dont protect car from dust, water, heat etc
2) parashute type with inner fiber layer
when cloth is new the inner fiber layer seems very soft to touch but biggest backdraw is its fiber attract drust particulars and thoes dust particulars stuck in fiber layer which cause light secratches to car skin while put on and take off cover
3) parashute type upper layer and light rubber coating inner side
this seems to be comparitivly better option as its inner side is smooth rubber coating so dust cant stuck in it further easy to clean its inner surface, i am using this type of car cover for my all 3 rides, and dust realy dont pass through this cover. picture attach
a good quality cover water proof however since car cover machine stitched so water pass through stitches 
never machine wash this type of car cover, never use strong detergent to wash its upper layer as these type of car covers made of water proof parachute and for this purpose differnt water resistance spary coating like teflone coating which distroy by machine washes and use to stronger detergents.
