I bought a set of tail-lights from a Superformance dealer and installed them in my ERA. I opened up the holes in the body, and the holes in the lamp retainer to maximize the lighted area. I rewired my car to separate the turn signal function from the stop/tail-light functions. I also used a Halogen bulb for the stop-light bulb to make it noticeably brighter. Here's a sketch showing before and after:
regards,
Jeff