Can anyone offer some advice

Our other car's (MGF) front right keeps going flat every few months! We did the old fairy liquid test and there is no puncture, the air seems to be leaking around the rim....has anyone gone down the road of having their alloy's sorted for this or is the best bet to f&%* it and go by some new ones and get the tyre refitted???
Theres a wheel refurb co. down the road but i'm scared of them eating into me alpine funds for no real gain

Any advice would be much appriciated (and worth an evenings beer & wine next time we meet up)
