The heater hose that wraps around the passenger side of the engine is a
preformed hose and seems to be overly engineered. While changing our hoses
on the 2000 D, I just got some cut to size hose and routed it over to the driver side.
It works great and is a much simpler install. Here's pics.

 

I think they route them on the pass side because the outlet is there. Also, if you have a rear heat/AC system, that pass side hose has a plastic Y fitting, with the input from the motor, one output across the firewall to the dash core, and the other output to a metal tube heading to the rear core.