DIY engineering at its finest.
Also perplexing is why you'd leave speakers in a racecar's lightweight door panels.1) well sry to ruin fun but it doesn’t mean they didn’t leave the vapor barrier still in
2) car is an E36
3) removing interior door panels and other weight isn’t uncommon on raced cars replacing with skins and pull strap
4) why you’d race a cabrio is perplexing