I recently purchased the ATR-Racing rear window from Austria. I suspect we are all more than a bit skeptical of aftermarket parts in general, but this product is outstanding (Arnold would be proud). They fabricate their own CF frame and glue it to the window just like OE, so no visible screws. They supply an OE perimeter plastic/rubber so you can’t tell it from OE. And it FITS perfectly. Lifting it was a heavenly endorphin rush. The OE window weighs exactly 35 lbs. Their 4mm street version window is 17.5. Combine that with the deletion of the OE struts and you get an 18.7 lb reduction. Lexan of course is a plastic so extra care will be required when washing, but just like our paint it can be polished if dulling occurs. At 2550 Euro plus 190 for the painted perimeter(which you want)for a completely fabricated piece is reasonable IMO. Of course shipping and customs fees up the price considerably. You cannot use the OE struts(which I had removed decades ago anyway). So what I do is lock the engine cover open and then I have a U-shaped piece of foam that I place on the top edge of cover and then simply lower the window onto the engine cover. Sorry I cannot source this foam piece, it was packing for something I purchased long ago. Disclaimer - Weight reduction methods addrisk and potential loss of value, but if you are a bit nutty like myself this product is highly recommended.