Quite often I encounter a vehicle that has exhaust with rather sharp smell similar to perfume. As far as I know this is attributed to the engine malfunctioning - normally working engine will exhaust ...
In my 2003 Opel Vectra, the cabin air smells of Diesel exhaust while stopped at e.g. a red light. The exhaust smell goes away when driving, and it also doesn't come back if I turn the ventilation off ...