Here is the sentence that hs 5 errors and I can't find them.
Here are some of the more bizarre suggestions add perfume to cars exhaust system
I think the perfume/car exhaust is probably intentional and correct, if someone has made the "bizarre suggestion" that we can mask the smell of car exhaust fumes if we inject a spray of perfume as the exhaust fumes are emitted to make emissions smell better! A bit like those terrible floral room deodorizers.
I get 3 punctuation, i capitalization, and two singular/plural issues.