I have a problem that need advising.When I switch on the air condition there are fuel smell in the passenger comaprtner.It is only obvious when I set it to recyecle air.Please advise anyone?

Check this out . . .

Does it smell after you fill the gas tank?

http://home.earthlink.net/~frankie66/cars-bmw_diy_fuelsender.html

I recently had the same issue. If you are filling the tank to much you will get gas in your carbon filter. But, most likely the problem is in your gas tank regulator located under the rear seat. Remove the seat and the padding, you might see gas on the top of the plastic housing. I had a small crack in mine. I took it out, cleaned it up and put epoxy around the crack. I have not had a problem since. You can buy a replacement part for around $60 (us dollars).