I thinking about installing a blind spot detector and one of the requirements is to run a cable and connector from the engine compartment to the cabin. Wonder if anyone has some good ideas on where is the best way to do that?

I have a 2002 xtreme

 

Try to find a harness already going through the firewall that you can run it through. Check for where the antenna goes through (passenger side)

You can always drill your own hole (after checking both sides to make sure its clear) and using a rubber grommet.