I mounted the PP Windshield and I can say for sure that there is a huge difference. Honestly, I do not even visually annoy me anymore. I do not like the windshield being transparent. It also vibrates at a higher speed, but that should be normal. More importantly, it deflect a lot of air flow. Something that is important to keep in mind when it comes to night time rides: the windshield reflects the light from the headlight, but it is not so irritating or distracting ... so.
About the belly pan: it is carbon-fiber and it is identical to PP one. It is purchased from HF Carbon Germany (Link
). Btw I've changed almost all plastic parts with carbon ones. Again with HF Carbon. So I reduced the total weight of my motorcycle by almost ~3 kilos. For example: The difference in weight of the plastic belly pan to the carbon fiber is almost 3 times. Unfortunately this part is at least worthwhile to be carbon for several reasons. First you can not see and appreciate the fact that it is carbon, and secondly it is the closest and lowest part to the ground, which automatically makes it the most vulnerable to damage. My advice would be to buy a plastic belly pan (PP Front Spoiler aka belly pan - Part Number: 64108920044) instead of a carbon fiber because it will not hurt your heart when you hit a stone or hit the asphalt.
you can find an alternative to HF Carbon, but I do not know what quality is.
Warning: You need to be careful when shopping carbon parts and read the description because it is very common to find parts that are not entirely carbon-fiber, for example they are made of carbon+fiberglass - to be cheaper, but more fragile and heavier etc.
To share some more experience about HF Carbon:
The parts come perfectly packaged. Their quality looks and feels almost perfect. To be more specific - Their outer side looks perfect, but the inner could be a little better finished. Two of my parts needed very light finishing (on the inner side), but everyone with little experience could do it. The communication was great, I had a lot of questions and all of them were answered in time. At one of the places the embedded metal threaded nut is peeled off from the carbon, because of excessive tightening, but a little glue fixed it. So be careful how you tighten the bolts. I recommend using of threadlocker instead of very tight tightening. I use Loctite 243 (blue, middle strength) and it does a great job.
I remain available for questions