stackz, you are a braver [or maybe more foolhardy?
] man than I. From the looks of the aftermarket X5 hitches I've seen, like that e30cabrio? yanked off his to mount the OEM, no way I would pull a 21' boat behind one. On the other hand, you new owners of OEM westfalia hitch kits will be impressed. Clearly engineered to manage the tongue weight and distribute the tow load across the unibody. That said, I'd stay within specs [the 8' long, 4"+ drop shaft] when pulling two tons or more. Do read the long DIY before you start the installation, and having two to lift and adjust the kit is very helpful. A couple of items are counterintuitive ..... also, think about your trailer brake controllers if your tow doesn't have hydraulic brakes [like the Uhaul trailers I have used to date]. I still need to install one for when I get a new horse trailer this Spring, and will probably get the RF 'remote' version of the Prodigy to avoid messing with the X5's wiring.