I had a Volvo pull up behind me at a junction. It was a busy pell, and I had to sit there a while and wait for a moment. The driver gives 3 or 4 toots, which seemed a bit pushy - but I checked nothing was hanging off my bike, and tried to put a bit of distance between us but he ended up tailing me for a spell.
Reviewed the footage from the Fly6 (first time I have looked since inspecting the image quality) out of curiosity - he was tooting to get a friends attention and waved to them.
Looking back, he kept a respectable distance and he seemed genuinely happy to see a friend when he was laying on the horn.
Cheered me up a teensy bit.