idale

I used a HeatShield brand custom-fit (roll-up) on my Passat for years and it worked really well. Right now I'm using an Audi shade because a friend traded in their Q5 on a Q7 and so didn't need it anymore, but it curls up on the edges so it's not offering full coverage like I had with my old HeatShield.

I'm sure there's other brands of custom-fit shades that would work, too, you just want something that's reasonably thick (if you're in a hot climate, that is -- I'd think milder climates it's more just having something shading the interior from the sun, insulating or otherwise) and that will offer full coverage of the windshield.