I have a Saddle (tan) top but my liner is dark gray. Is your liner white also?? If so yes I can see that it might light up your back seat. Honestly I never notice mine, and I have driven alot at night with the top up. The instructions are pretty straight forward. Other than the "Man I am about to cut holes in my *&^%" Use the templates that they give, and make sure you have them dead on. I measured like 4 times and made sure that the templates were just perfect. And somehow I was off on one of the holes, Not bad but on the drivers side you can barely see it. Pissed me off non the less.
Side note, I spent 4 hours the other day making a build number for the front bumper. I could not find what font Saleen used so I had to create it myself in Fireworks and do a reverse print to the back of the Decal and cut it out with a razor. I seen a few cobras at the car show that had them and thought it looked good. I will post a pic when I get home.
Good luck and man it will look sweet with the bar. That is one mod that made a big difference in the looks. I am fixing to get the Speedster cover with the wind guard soon.
When are you planning on doing the install? I have to do some detailing on mine hopefully this weekend. I will remove the bar on mine and take some key photos of the areas that you will be dealing with, and the wiring area. Let me know. To bad you are not closer, as I could help with the install.