Jeep took the supercharged 6.2-liter Hellcat V8 out of Dodge’s most unhinged muscle car and bolted it into the Grand Cherokee, then rebuilt the driveline, brakes, and cooling system to survive it. The result runs 0-60 in 3.5 seconds and the quarter mile in 11.6, with a tow hitch attached. At $85,900, the value argument was the whole pitch. Read on for what made the Trackhawk possible and what to know before buying one used.