Yep I took a while on these to.
Ended up with Trunk liner :
Tailored Boot Liner to fit Tesla Model 3: Free UK Shipping on Orders Over £10 and Free 30-Day Returns on Selected Fashion Items sold or fulfilled by Amazon.
www.amazon.co.uk
standard amazon edition, I quite like the look of this, and it feels loose enough to get to the sub trunk, but sturdy enough for me to sling my guitars and amps in with a non stick component. Looks good, and nice reviews and it fits 2022! I was tempted by the 3d maxpider clones, but, I think they're great but too thick of me. I just need something to protect carpet and make the space waterproof.
Ordered the rubber 2021 / 2022 sub trunk and frunk mats individually at ali express: Got to be careful you do get the 2021/2022 variant.
HERE
I just need something that is waterproof, and can contain the odd spillage. I'll be using sub trunk organiser anyway for cans and components.
For sub trunk (rear), I'm intending to keep the charge cables / cleaning stuff / tyre emergency repair bottles, and ring digital air compressor etc so need something to stop it all rattling about. You'll be hard pushed to find something more optimally sized for £15 than this:
50x32 cm x 27cm organiser with rounded bottoms. I tested on the sub trunk floor mat, as I need it to fit on that within the sub trunk... and it's cm perfect for size leaving a little wriggle room either side (about 1.5cm each side).
It's all personal preference though. These'll do me without breaking the bank any more than it already is