I'm looking at a set of carbon fiber valve stem caps and wondering if anyone has experience with these. My concerns are:

Do they mess with the TPMS? (The Audi site linked below says they don't, but I've heard different.)

Any problems with fusing, etc.? My A5 will be driven in snowy winter weather with salt, sand, etc. and I don't want any problems down the road.

Here they are: Carbon fiber valve stem caps

Thanks.