Today I was driving with young children in the car when another car was at the side of me. The lane he was in was for right turn only. Instead of turning right though this man decided to try and speed up then pull in front of me as he was in the wrong lane. It's a common place that people choose to cut others up. I was in a line of moving traffic and didn't change my speed. I actually assumed he was turning. He then angrily beeped his horn and tailgated me the entire journey through town. Eventually on the next dual carriageway he overtook me and mouthed abuse as he went past. My teen who was sat in the front took a pic and made it look like he was recording him. The man slowed right down then and turned off into a big car sales place. He had the numberplate hanging on the front windscreen in red. So I assume it was a car he was picking up and he was working for the company at the time of his delightful behaviour. I was very tempted to follow him in and tell someone but I didn't. Should I have done?!