Gas smell after fill up - suggestions for mechanic

2008 Mazda 3
Hi, I just joined the forum. I have a 2008 Mazda 3 and a 2017 CX-5. I live in the SF bay area and my son live in Las Vegas. He has an '05 Mazda 3. When he fills the gas tank the car wreaks of gas. I read some forum posts about leaks on top of the tank around the fuel pump seal. If that's the problem he's not mechanically inclined enough to repair it so I'm looking for suggestions for a mechanic in the LV area to take a look at it. His solution is to just fill it half way. I'd like him to get it fixed before he either passes out from fumes or catches on fire. I appreciate any help on this.
2014 Mazda3 S GT auto, 2008 MX5 6-speed
Ask him if there is a check engine light, which may indicate a code P0442 (evap emission control small leak detected). Most auto parts stores will read a code for no charge.
2014 Mazda3 S GT auto, 2008 MX5 6-speed
Possible causes
Missing or loose fuel cap
Incorrect fuel filler cap used
Fuel filler cap remains open or fails to close
Foreign matter caught in fuel filler cap
EVAP canister or fuel tank leaks
EVAP system hose leaking
Fuel tank leaking
* What does this mean?
Tech notes
The P0455 it’s a very common code, because the code is set if the gas cap is loose or missing. Start by tighten the gas cap and clearing the code. In most cases the code can be clear by disconnecting the car battery for about 30 minutes.
2002 Mazda Protege 5
I had the same problem and what is was I dreaded. The plastic ring on the top of the gas tank was cracked. A known problem. The part was expensive but i replaced it and it's fine. There is a video on youtube of a guy changing it which helped.