I got rear ended by one of those three wheeled contraptions last year. It was a completely ordinary situation where any normal roadworthy car would have made a stop and avoided an accident. There was plenty of space to stop. But the morgan could not stop. I could hear his tires squealing behind me for what seemed like an eternity before he crashed into me. Of course it did not have antilock brakes (they have been required for cars in the US for about 25 years now). The front wheels were these thin motorcycle tires that had no stopping power. I am not sure the rear wheel even had a brake on it.
My car had some bumper and trunk damage. The morgan was totaled. The Morgan did not have much of a front bumper and took all damage straight to the radiator and engine block. I drove of the accident site. Me and several firefighters has to push the morgan off of the accident site. I did not get injured, the morgan's driver crashed into the wheel, and had pain in the ribs. The Morgan did not have an airbag and I did not notice a seat belt.
Do yourself a favor, never get into one of these things, do not even think of buying one.