The first and cheapest thing to check is the gas cap. This has been the source of many a gas smell on this forum. You can get just the gas cap gasket or the whole cap. The cap is cheap so that is a good route to go. Now I just went through the same deal and in my case the cap was only part of teh problem. I also had to replace all the fuel hoses. They may look fine from the outside but once I pulled them off I found they had large cracks all the way around. I then pulled the tank (123 Wagon) replaced all the rubber fuel hoses and now I no longer have any gas smell. Remember you may not see any fuel leaking but it only takes the smallest amount to cause a strong gas smell.