Been using Calif car Cover lightweight cotton covers for about 35 years - the same ones, in fact.
They were maybe about $60 back then.
Wish I'd bought more of 'em at the time.
The thing about elastic ones I don't like is if you need to open a hood/trunk/door, they want to come off the car.
especially on the cotton part, thickness ? depends on a few things. The thinner will be more prone to letting dust etc through, washes easier, dries easier, but also provides less protection against damage if something should bump or scuff it. myself I prefer a medium to thick 100% cotton
