Hello beat1 ....... welcome to our strange noise generating machine .....
Do you have any exhaust/power modifications .. ?? If so, what ..??
If not, have you done anything to the engine or exhaust lately .. ?? (other that what the dealership did)
Have you changed gas supplier lately .. ??
If I were going to start messing with stuff, I'd start by checking the exhaust heat shields, followed by the exhaust connections.
From your video and description, it sounds like my FR-S starting up ....
humfrz