Car paint, light cards, and FG

[JeffPatton]

I know, probably a confusing title to this thread but there are several aspects to this issue.

So, let me start off with a few real world car paint examples:
http://jeffpatton.net/Tests/paint-ex-01.jpg
http://jeffpatton.net/Tests/paint-ex-02.jpg
http://jeffpatton.net/Tests/paint-ex-03.jpg

Now, I have a real simple studio setup in mental ray with a few photometric lights and some light cards (using an output map) just to give some proper reflections from my actual light locations.

Here's a cropped sample render using the car paint shader:


Notice how the reflections from my light cards aren't pure white as I would expect. If you look at the real world examples at the beginning of this post I chose those examples because of the dim lighting, yet still bright highlights on the paint.

So, to make the reflections brighter I can increase the output map settings on my light cards...but naturally that borks up my lighting by adding light since FG is enabled...but the reflections are white as shown in this render:


I've tried to use several of the shaders on maxplugins.de that deal with controlling the ray types to try and eliminate my light cards from contributing to the FG solution regardless of how high my output map settings go....but no luck so far.

The only solution I have found thus far is to turn off the reflections option on the car paint and use it as a base material in a shellac or composite map. Then use a reflective material for the "clear coat". This method has it's highs and low's as well. One low is that it's harder to control the colors because I'm having to mix in new colors...but on the bright side now I can use a bump map on the clear coat layer to simulate an orange peel effect. Here's an example using a composite material:


For a car paint comparison here's a maxwell car paint material from their website:
http://jeffpatton.net/Tests/Adrian-MW-carpaint.jpg
and a Vray carpaint created by using a Vray blend map:
http://jeffpatton.net/Tests/paint-vray.jpg
Ignore the fact that I didn't let that image completely render. I figured I had enough rendered to show the effect.

In the Maxwell version you can see how the reflection is bright white as expected with the moderately lit environment. In the Vray example, I had the lights too bright...but I'm sure the reflections would still be bright even if the vray lights were less powerful.

Sooo, finally my questions:
1. How can I make a powerful light card that does not contribute to my FG calculation.
2. Shouldn't the car paint materials reflections be brighter? I'm thinking that when I use the shellac that's an additive mode therefore that's why the reflections are brighter? I know what mode it is when I use the composite map...so maybe the car paint reflections should be in an add mode?