I purchased the model y cover for the outdoor on from Tesla site.
fit is great - covers everything end to end and even the wheels. Love the fit a lot.
within the first three days it saved my car from multiple bird droppings and tree saps. That made the cost worth it alone tbh. It wipes off pretty easily when you have the cover on the car.
a few other points after regular use of this cover:
the inner lining is a soft plush kind of material (kind of like fleece?). It won’t scratch the car but it will catch leaves and any debris on the floor if/when you drop the cover.
as for putting the cover on and off - it’s fairly easy to do it for one individual but of course easier with two. It takes me about a minute now that I’ve gotten the hang of it but the cover is heavy and especially when you’re trying to scrunch it up and set it aside when you’re removing it (I place it in the trunk when I’m about to drive off)
also FYI - this does bring the car temp even warmer when parked inside and outside. The inner lining kind of traps the heat since it’s this thick almost fleece like material
No experience with Model Y but I bought an outdoor cover (probably similar; maybe made by same company?) for my Model X and am very pleased. It is light gray with white liner. (Probably artificial fabrics.) That soft inner liner seems to protect the paint. Fits snugly over side mirrors (I have them fold inward to make that easier.) Seems very well designed and built--characteristic Tesla accessory quality. NO cover is totally easy to install and remove, but this one goes on and comes off well. And with experience it is easier to do (just have to learn to orient front and rear). It has an elasticized bottom edge. Plus you can lock it underneath the car with a cable (not included), if necessary. I have already noticed how many car washings it is saving me from. Really reduces the dust and stains if you use the cover religiously when you park at home and/or work. May possibly reduce damage from very minor impacts (e.g., like from a small branch or neighbor kid's soccer ball hitting the car). And definitely seems to eliminate the problem of bird droppings.
<Surprisingly, I haven't noticed any droppings on the cover itself, which has a dull finish. Is it possible birds choose to void themselves over shiny surfaces (like it was over water)? I know birds do avoid defecating in certain areas (near a nest) to avoid predators. Around here it is crows, scrub jays and, believe it or not, hummingbirds.>
Downsides? Like all full-sized car covers, it's big. A few minutes to install or remove. Nighttime cats like to (territorially) spray at the bottom edges and/or sit on on the giant cat pedestal. Let them. The car's interior still gets very hot in summer (I'm in the California Central Valley), but probably not as bad as without a cover. Also, it maybe nullifies some Sentry Mode functions--video cameras? (However, the SM alarm still works with cover on. Found that out the hard way.)
I haven't tried washing. Probably let winter rains do that.