My most recent Death car would be the Speed 12... I got it tuned up to kill everything at 600PP on Nurburgring.
1027 HP and around 1200 KG. Horrible understeer if you hit the corners wrong... takes off like a jetliner on the first jump if you don't brake before it. It chewed up all the race cars it came across in that PP range including the 2J, a 787B, and a GTR TC.
Street cars can keep up a little better... an R8 came within 5 seconds of me.