Ran across this information showing that low-floor FWD ProMaster should be much easier to pull off than a RWD Mercedes Sprinter.
It appears these guys have been building low-floor chassis based on Ducato for some time, and now seem ready to expand to USA version with ProMaster. There is a pdf download in English for ProMaster van. The compact air suspension that allows tandem rear axles is interesting, although I can’t tell how axle movement is controlled.
Youtube is a short overview based on pictures:
You can see pictures in more detail on their European web site by going to “FOTOS”
http://www.coxx.be/x-low
Or go to photos directly. Must click on photo to see entire view which is much bigger (at least on my computer):
http://www.coxx.be/x-low-photos#
Specs indicate roughly 16-inch floor height, which would leave about 12 inches of ground clearance – plenty for road use. Doing a similar chassis modification on a van 90-inches tall (low-roof ProMaster) would leave plenty of headroom for a man my height to stand and walk around. May not be worth it, but it shows it can be done.
Exhaust is indeed routed out the side to simplify chassis; which appears a lot like a low floor trailer. Basically that’s all it is since there is no drivetrain.