Found this little clipping issue by accident while trying to get the Peelieve In Yourself accolade, so I had to go back later and get a recording of it. Sadly, the audio didn't seem to make it, but that's not a very important detail.
This glitch works on both the Peel Trident and the Peel P50, though it's more reliably done using the P50. I attempted it using other cars (as shown at the end of this video), but they just bounce off. The only other vehicle that it works with, that I've found, is the BMW Isetta, another tiny car.