Having installed the OEM hitch, I believe they are static (using your terminology). The ones removed are typical shock absorbing types and they are replaced with solid steel pieces that come with the hitch. That said, I believe the plastic bumper would probably crack regardless.

I have been towing a 20' vnose enclosed with a loaded weight of right about at 6000 lbs with my 4.4 for about a year now. I am using a load distributing hitch, Prodigy and have been loading race cars with engine to the rear to try and maintain proper tongue weight. That said, I do have moments when I feel the rig is not so stable, especially around 70 mph. Plus, the car will vibrate at those speeds for a reason unknown to me.

As impressed as I am with this little car's ability to tow, I will likely upgrade to a 3/4 ton truck for towing anyway 1) because I'd like to be able to throw more equipment in without worrying and 2) tow a larger trailer in the near future (20' vnose is a tight squeeze for an E36). I'm not willing to go beyond the mfg's rated tow capacity for both safety and liability reasons.