¯\_(ツ)_/¯Are you sure it was friendly and are you sure it was a thumb that was up?
All I can say is it was short beep not a prolonged blast, but I didn't see the digit in question as he was on my N/S as we passed him in the queue for a roundabout. Mrs Bav reported the thumbs up and speculated he was confused and that he mistakenly thought he was driving a Transporter.
![Giggle :giggle: :giggle:](/styles/default/xenforo/smilies/giggle.png)