The Tesmanian one says it has '2 self adhesive magnets' now on its V2 - so looks like this is going to be the solution for folks.
Tesla Model Y Sunshade - The Tesla Model Y Sunshade offers enhanced protection and comfort. Made from lightweight mesh fabric, it reduces heat transmission into the cabin, keeping it cooler and more comfortable. Its sleek, one-piece design adds elegance to your vehicle.
www.tesmanian.com
BTW, that one you linked to had a 20% off coupon - so it's a great deal at 42.77 w/ tax! I think I'll pull the trigger on that and add my own magnet.