This has to be the most mis-quoted and misunderstood legislation in the entire industry.
Quoting this legislation when discussing modifications shows that you not only don’t understand the legislation, but you also never bothered to read your warranty contract.
MM does not apply to vehicle modifications. The term “aftermarket” in MM refers to replacement equivalent parts manufactured by someone other than the OEM. So replacement oil filters, air filters, wiper blades, etc. An example would be a consumer coming in with an engine noise concern; the dealer/manufacturer cannot deem it non-warrantable just because the oil filter is a Purolator and not an OEM. However, if they disassemble the filter and find that the media came apart and damaged the engine, then the failure would be non-warrantable.