When BMW releases the parts list on the HP4's we will have parts numbers.
The carbon bellypan off the Comp. is my favorite. It look different than the bellypans from Ilmburger. The BMW Comp. one has nice clean/sharp edges.
The HP4 base bellypan looks more like an extension or multi piece on the S1K. http://shop.ilmberger-carbon.de/carb...-racing?c=3121