I haave a 1998 audi A-8 tht has about 189,000 miles aand for the past 2 yers now everytime it gets below freezing there is a wicked baad smell of gas in the car.I dont know if there is a blocked vent hose or what to look for plese help as I have two children in the caar.thnks charley

 

Do you smell it in the trunk also?
Under the rear carpet are 2 access plates. Under one (right side) is the fuel pump and gas gauge sender. The other side is a second sending unit. Both are secured with a large plastic ring nut with a large o-seal under it. Both of these, of course are direct passages to the gas tank. Might be worth a look and smell around these...fuel lines connect to right side (at fuel pump) also.