I ran mine through the center section via the 625 plastic bushing in the left most bay, along with some of the wires going out to the wing. One center section bushing wasn't enough for me including the wires for the lights, adahrs (mine is in the left wing), pitot heat and nav coax, so I got Van's permission to add a second 625 bushing one one bay inboard in the center section. They were very specific as to where to put it! To get the tubes into the fuselage, I also had to drill a second set of holes aft of the main wing hole in the fuse. I probably have a picture somewhere, but not accessible currently.
Once I got the tubes forward of the center section, I ran them along the floor on the left to the firewall then up.