My 2004 Cadillac CTS has a cracked dashboard panel. Crack appeared to have been caused from the sun? I would like to replace the damaged dash panel but cannot find the part? Any suggestions?

I had something similar happen on my 2004 CTS. The car would not crank, and I recall the security light was on the dash. The key could be turned off, but not quite far enough to be removed.
The key can be removed by sticking a small pin or screw driver in a hole under the steering column... maybe 2 inches from the actual steering wheel. I recall there is a small cover or plug in the hole that needs to be removed.
You can let it sit and occasionally try to start it. My did start once more.
I ended up having it towed to the GM dealer and they replaced the ECM for about $500? That took care of it for a couple years, until I recently sold it.

If the auto headlights won't come on then there is too much light making contact with the sun sensor on the dash.

There are vehicle upholsters that have the ways and means of redoing the dash of most vehicles. Or go to the wreckers and get one from there. A good investment when you have had it replaced is a dash mat to stop the sun damage.

This depends on the type of crack ... if it is from the sun drying out the material and shrinking it a quick-fix will probably suffer the same fate and look worse when it happens. If the crack is from abuse (like when I threw a bunch of 2x4 lumber on mine and caused a crack) then you might be able to find some repair goo for it -- ask at an auto-parts store and they might have it ("repair goo" is not the real name of the material, but I don't know the real name off hand). Make sure you let the person who is helping you know whether your dash is real leather or synthetic material as the type of repair fluid used will vary with color and type of material to be repaired.
If you have a real-leather dash you might even be able to go to a leather-goods store and find a repair fluid there -- it would be basically the same as fixing a tear in a leather jacket. I know that the repair fluid exists, but I do not know the name ... just that I have seen it advertised on late-night television.
If you can't find a repair fluid that will work with the material that your dash is made from, or if your crack is caused by sun-aging of the material, you might have to replace the piece of the dash panel that is cracked to get rid of the damage. Just bare in mind that if your dash is sun-faded it will be very difficult to match the exact color with a replacement .. and you might be more annoyed with the color difference than you were with the crack.

the plastic ,happens to lots of other cars as well especially in the sun

Automotive trim shops can usually repair these dashes

Well for start don't take any passager. Check air bag connection. The fuse box. Replace it from junk yard if it's damage. Try erasng the code if it appear then replace it. Check connection too.

How can I increase lighting on the dash control panel in a 2004 Cadillac CTS

T/C would be traction control i would think

Robert