[thewebguyd]

I've seen flashing third brake lights too.

I don't get adding flashing lights to brake and tail lights. It's actually worse, flashing lights make it harder for us to judge distance as now there's no steady queue needed for depth perception. It's why when cycling I've always opted for a solid taillight instead of the flashing ones.

[toast0]

Flashing third brake light (in the US) is usually a dealer profit addon. Personally, I think these violate federal vehicle safety law. I'll add a link to a federal letter that I think agrees with me [1]... But no enforcement means dealers alter the wiring harness to add these on to all their inventory and add a line item on the bill. They'll remove it if you complain, but the wiring harness has been altered.

I'm ok with factory strobing on hard braking, and I think that is permitted generally.

[1] https://www.nhtsa.gov/interpretations/20288ztv

[potato3732842]

They're not altering anything. This isn't a stereo shop in 1990. They're literally just getting paid to plug something in.

[toast0]

From the install guide [1] under "Installation Instructions, General", step 5 is:

> Cut the positive wire to the third brake light and strip the insulation from both ends of the cut.

That's altering the factory wiring harness. That's an extra junction the factory didn't authorize and when it fails, the factory warranty won't cover it, because the wiring harness modification lead to the failure. All so the dealer can make about $250 extra on a sale.

If these were built as a module you plugged in between the wiring harness plug and the light module socket, I'd have a smidge less hate for them; but there's too many plug types for that, and there might not be enough room anyway, so the dealer has to cut into the wiring harness for this ... if there's a real benefit to flashing brake lights, it should be standardized and done by the manufacturers.

[1] https://pulseprotects.com/wp-content/uploads/2023/09/Sales-R...

[potato3732842]

They literally make drop in bulbs

https://www.ebay.com/itm/184234748289

[toast0]

That'd be fine, I guess. But these guys [1] have more dealer sales outreach and they sell a module which you hack up the wiring to add.

[1] https://pulseprotects.com/

[sokoloff]

I’ve seen a few cars that have strobe-then-solid brake lights from the factory, where the strobe only fires under hard deceleration. That seems like a safety win to me. (Remember it being on a high-spec Mercedes SL, and I’m pretty sure it was stock; looked it up and Mercedes calls it part of “Adaptive Braking”.)