Harley I gather you are talking about this mock-up.
Those group of 3 are Hella 9001, the same ones that FFR uses right now on the 818. They are 66mm (2 19/32) dia. They can be found from a bunch of places. Here is one place Susquehanna MotorSports
The idea behind the 3 Hella lights is to have a module that is flush with the outside of the body and the vert "bars" and the vents are recessed somewhat like the Vantage. Here is a pic of the Vantage to give you an idea.
Sorry for kind of hijacking the thread somewhat. Didn't know where else to post an answer to the group of 3 tail lights.
David
Yes, thats the look I'm going for.
I'll check out the hella's, I didn't see that they were the same model as our turn/backup lights.
Harley
Bought 2002 Donor Jan 2014
First Start Jan 18, 2015
First Drive Feb 14, 2015