Can Dealers Tamper with New Car Tail Lights?

My brother and his wife just purchased a new Toyota vehicle, parting with nearly a year's pay in the process.

During price negotiations the dealer demanded $400 for a dealer-installed tail light "pulser".

I put one of these on my Avalon years ago to blink the high-mounted tail light when the brake lights turned on. I think I paid $8 for the blinker module on EBay and installed it in about 10 minutes.

Can Toyota dealers monkey around with vehicle safety hardware like tail lights without running afoul of NHTSA rules or Toyota's supervision?

Is a dealer permitted to tamper with any safety hardware: brakes, seat belts, fuel tank shields, etc?

BTW, this vehicle did pass to the buyers with the pulser on it, despite the device being deprecated during price negotiation.

 

I did an internet search on the pulser and learned that it's a common dealer strategy to raise profits on new car sales.

One poster on another website mentioned that his dealer wanted $1200 for the pulser.

I think the pulser's charge always gets negotiated away but serves to distract the buyer from the reality that he's paying sticker or sticker-plus price for the vehicle.

If I were a car manufacturer I'd yank the franchise of any dealership that demeaned my product like this.

If you have to resort to sales tactics like this to be profitable, you're in the wrong business.

 

I remember telling my brother something similar to "walk away...bad dealer". He countered that inventory in Midwest Toyota dealerships is still low two years after the end of the pandemic, or is a consequence of a new "keep inventory off dealer lots" decision by Toyota.

Brother wanted a vehicle with few options and few of these exist.