[Bob's Flat-Six]

I saw a Spyder that looked like the real deal heading East on the 101 in the Glendale area. It had red primer spots on it's silver.
I was in a truck and he was moving right along in the fast lane so it didn't last long enough. It had early License plates that I think had the yellow background ? I did hear it's motor, and it didn't sound like a regular 4 banger.

Anybody know the car ?