Yo, I reckon that was me, my is Car is Cosmo Blue, though it can easily be mistaken as black. I've been working longer hours this week so I've been on the road at different times to normal. I do remember waving at a light blue 156, I have had waves from a Red 156 GTA, and a blue 147 this week. I always wave on the A140, there are 3 regular wavers that I see most weeks!
Though there is a lady in blue Brera who I've been waving at for nearly 2years, never waved back, must think I'm right looney.
If it wasn't me, nice to meet you anyway, I'll keep looking out for you.