oh, got You wrong then.
With that power and in the car, I am not fumbling around with a homebuilt driver
(also all the parts together will cost nearly what the driver is, so ...)
its simply:
power in contacts from car to Ampere driver
out Ampere to 1st led, to 2nd led, back to driver (= setup in series)
(the led then as aspherics into those cheap projector beam fog lights)