| I used kerosene and a wood scraper on the undercoating. Then a 409-type degreaser and lots of old rags to wipe it down to original factory paint (underneath the undercoating) 
Then everything was repainted and self adhesive aluminum heat/sound insulation panels affixed in strategic areas including trans tunnel, next to turbos and downpipes and above exhaust pipes. The heat insulation has been in place nearly five years with no delamination. 
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