Grease the front end. https://www.gomog.com/allmorgan/front.html
It sounds like it needs it.
Check the tyre pressures they should be 22 psi.
Grease the rear leaf springs.

I got exhaust blow back on my Rover +4 but only at high speed. You definitely shouldn't get a petrol smell. Check the hoses.

JohnV6
2022 CX Plus Four
2025 MG ZS EV aka Trigger