I recently purchased a 2002 Ford Explorer XLT with the new V6 engine. Had a chance today to run 40 meters for the first time on a trip to Wichita.  Would you believe - NO NOISE.  I guess Ford finally cleaned up all of the RFI.  I was really surprised!  It will make HF mobile operating much more enjoyable. I'm using a Yaesu FT-100 and roof mounted Comet 40 meter antenna.