[Pete.]

I had similar smells and concerns when I first took delivery of #48 even though it is fuel injected. I checked all the lines etc about three times and took the car back to DRB for them to check as well. No fault found.
I asked my brother in law who has been motor racing all his life to come over and see if he could find anything. His comment as he walked into my garage was "smells just like a race car".
I have never worked out where the smell emanates from, I suspect that there is enough residual fuel in the stack pipes after engine shut down to cause the smell. Even half a teaspoon of fuel will stink up your garage if it is not well ventilated.