Can anyone offer some advice?

When I fill up my 2003 Subaru Impreza I have to do it very slowly, otherwise the gas pump stops often. This problem started in the summer, but has gotten progressively worse, to the point where now I can only depress the lever on the pump very slightly.

I took my car into have it's winter tires put on in November and asked the dealership to look at the problem for me. They checked the error codes and then told me that this is a common issue with Subarus, and there was nothing they can do.

I'm not sure what the deal is with modern cars, but on the older cars I have dealt with there is a small pipe which goes from the fuel tank, through the filler neck and out to the atmosphere, ensuring that the increase in air pressure caused by filling your tank doesn't turnoff the pump until the filler neck becomes full. Originally I thought this breather pipe may have become clogged, but the service guy at the dealership assured me that there was no such pipe on my car. Is he off his nut?

Has anyone experienced this before? How did you fix your car?

Thanks in advance!