Matt and I have discussed this several times. Does anyone know or would it be state by state. Can the break light strobe for a few seconds before turning solid? Either way we are going to do a third brake light on the teeners and I am going to add one to my 911.

Prohibited by FMVSS 108. Where you see it being done, it is technically illegal.

Mercedes has petioned several times to get small scale exemption to study the safety effects in US. Denied by US Gov't that is too dumb to get out of its own way despite feature having been deployed in Europe for over a decade. In Europe, the flashing is only triggerd in high deceleration, emergency stopping scenarios.

https://www.federalregister.gov/documents/2...on-from-federal

Lest you think they have gotten smarter since 2005-2008 era petititon by Mercedes.
https://bmw.oemdtc.com/733/brake-lights-fla...bmw-motorcycles

Here's what they have to say about the BMW recall:

"What could happen?
During emergency (hard) braking, the stop lamp flashes which is not allowed in the US market due
to a Federal requirement. A flashing brake lamp could be confusing to drivers following an affected
motorcycle, and could increase the risk of a crash."

Hypocritcal given NHTSA has no real public data that has been shared with OEM's and NHTSA refuses to allow any study of high-G flashing brake lamps on public roads but yet they allow Tesla's out on public roads to study Auto Pilot / FSD (full self driving) which has lead to multiple fatalites.

US Gov't also inept with respect to forward illumination. Rest of World gets active headlap illumination that is able to more brightly illuminate the roadway while shielding oncoming drivers from high beam. This is done via active mirrors and/or active LED matrix. US literally decades behind. Same as was the case when Europe migrated to Halogen bulbs way back in late 60's or early 70's yet US remained in the dark ages (pun intended) of sealed beam headlaps until 80's.

PMB set up one for my 6

Bob BClick to view attachment

A 3rd brake light that flashed a few times before going solid was an OEM standard for a few years.

You beat me to it. I've been searching for a led strip to do the same thing

I think it would be more visible to SUVs then the under targa light.

Thanks @drem914 - smart install. Those led strips are pretty ubiquitous and can be found many places. the black pcb/tape is nicely done.

It would replicate pumping the brakes and it is an attention getter. That's all it would need is maybe 5 flashes and then solid.