So, I haven't been updating very much in the past year (sorry), but here's some new info. As mentioned, I've switched to vray. This was the first thing I made while testing it (around April 2009).
Some things to note about this image:
It is an "impossible" lighting setup in the real-world, and when we are tied up in physically accurate lighting, we need to remember that lighting direction doesn't always have to follow real-world rules. The goal of this image was to recreate a particular composite of images where lighting was tuned for each specific part of the interior then combined in photoshop. The overall image works, even though lighting cues/directions are all mixed up.
There are about 30-40 rectAreaLights in the scene, split up into "zones" and there are lots of light exclusion/linking going on to keep one zone from affecting another zone. Zones were broken up into seatLeft, seatRight, Steering Wheel, Side Door, Shifter, Dashboard, and Dashboard Central. This render is just about raw from Vray, and very little has been done to it other than some retouching and minor CC.
I wouldn't call it totally finished, as there are some texture problems, and could use some post love and color grading, but this served as a great test to see how our switch to vray might go. I took about one week to produce this image, from having never used vray before. I'd say this image has some very inefficient render settings, since I wasn't quite versed, but the quality and relatively low learning curve (from MR) convinced us to make the switch.