I have been getting a gasoline odour smell for about a decade now, particularly on hot days. I believe this is due to the aged hose in the EECS system, as I found in this article. This looks to be the part for the Canister Purge Valve (Part number E9DZ-9C915-A).

As I looked at it, I noticed that the part in the second picture...

EECS system gas vapour odour - 1994 V6 Mustang