gas smell on a e36 is usually a on top of the tank problem, ether a o-ring on one of the two senders has died, or the **** designed plastic/rubber pressure line from the right side (fuel pump) is starting to leak directly infront of the tank where the steel pressure and return lines start and the rubber lines from the tank end. being fuel level related id guess it's a o-ring, theres a sending unit on each side of the tank accessable from under the back seat, pump on right gauge on left
all america wants is cold beer warm cat and a place to take a poop with a door on it