I was looking over the https://www.superbrightleds.com/ site and see they are now offering CAN buss LEDs.

Looks like the CAN buss type just draws the same current as an incandescent. So I guess they have a built in load resistor which puts the same heat as the incandescent into the light fixture. Pretty dumb idea. At least using the external load resistor you could move that heat outside the fixture. You need the load resistor with ECU blinker control and or ECU signaling a bad light. We are lucky that our DeLorean uses a "blinker" that we can replace with an LED compatible blinker.

Like the dumb idea of making a festoon with a switching regulator which makes the bulb non-dimmable. Most every car dims dome lights on and off. There is a way to make switching regulators dim but I have yet to see anyone do that.

Some of their specification data sheets list that the bulb is dimmable or not. Some specification state instant on and off but I don't know if those are switching regulators. I wish they would standardize their spec sheets.