My first question to you is why do you think you need a roof sunshade ?
The only sunshade I bought is this
windshield sunshade that I used in both my Tesla Model 3 and my Model Y. It fits both and it is perfect for when you keep the car parked in the sun. When you are ready to drive, just start the preconditioning of the cabin 5 minutes before you are ready.
From my experience with both Model 3 and Model Y, if I keep the HVAC in Auto I don't need the sunshade above the head when driving long periods of time in hot days. And the Model Y has a heat protection on the roof.
My advice for you : drive it enough to get an idea of what is the reality (stop listening for those who want to sell you unicorns) and then make a decision. In my usage case, a roof sunshield on both Model 3 and Y isn't worth a dime.
