in the last day or so the wagon has developed a strong petrol smell. I checked the fuel cap, which seems sound. There are no obvious leaks anywhere. Tank is full. Do these cars have any places where they typically get fuel leaks?

Check the charcoal canister.

Had a similar problem, was the bit of hose connecting the filler pipe to the tank. Tighten the clips, really tight!

Had a similar problem, was the bit of hose connecting the filler pipe to the tank. Tighten the clips, really tight!

Yep. OP, stick your head under the back of the car and look for fuel stains at the rubber hoses joining the filler and breather pipes to the tank.
Also check the fuel filter hoses and fuel pump, both are on the rear of the tank of the wagon, for stains.

Do a search.

Lots of people have had success changing the fuel cap, myself included.

Mine was the original, car had only done 80,000km, it looked perfect - but it was no good.

Others have replaced with aftermarket ones from Repco etc - which didn't work. They ended up buying genuine mitsi one from a dealer and the problem was solved.

Ok, all sounds good, thanks

I also had a fuel smell in my sedan and to my surprise changing the fuel cap got rid of that smell.
Mind you, with the old cap, when I would open the tank to fill up at the station it wouldn't make that hissing sounds of pressure escaping which was a clue for me. Have a look if yours is the same

+1 fuel filler seals, long story B-Double removed passenger side of my TH - Listed on the repairs was fuel filler pipe and seal, never had the fumes after that....