Hey Bjoern,
The XJ220 is one of my faves. But why sell it with ONLY A V6???????????????????????? arrghh... It needed their V12, was designed for the V12, and they went with a V6...
I had friends that worked for Jag as test drivers. They had to move to Texas for a year for the XJ220 endurance and US registration testing, running it on a huge cicular track daily. Two 220's were lost to possible frame failure, breaking in half for no apparent reason. 2 Souls lost. The people I knew all made it back home to Phoenix safely.
I cant imagine driving at near 200 MPH all day long, for months... I did do 120 MPH daily for about 7 months with a Euro Range Rover German Edition, which needed 'Autobahn' life testing. We finally got it passed.

But man, could you imagine life in a Jag for a year at high speed???? lol.. . dang..
Sunrise, prep the vehicle, check the tires, oil, clean the windshield, get in, warm it up, idle to the track, turn on the temp equipment recorders, start the paperwork, log your mileage and time, then hit the track, helmet on, flashers going, (headlight strobes). Run it out of fuel, which on an older Rover was about 1 hour 45 min's, then to the fuel paddocks to refuel and scrape off all the bugs, butterflies, and sometimes bird debris.
One guy hit a jackrabbit. Luckily it didnt do any damage to the Discovery he was in. It was huge.... Hitting one of those at 200 to 220 MPH in a low slung Jag XJ220 and at night (they ran at night also), would have been disasterous, like being shot with a military shell in the nose. This particular jackrabbit was as big as a medium sized dog. I havent seen one that big before. Havillina pigs would cross our track, but we could usually miss them. They feared us and usually ran for it before we got super close. There were a family that lived at turn one.
Those were the days, lol...
Side note; We (Land Rover Developement) were one of several manufacturers that tested at the Chrysler Proving Grounds (when it was open). Volvo, Rover Cars, Shelby, and sometimes Honda would also test out there. We (they) also brought in test vehicles from around the world, such as a Lambo, Renault Espace (that was cool), the GM electric EV1 (that thing was awesome...............) and a few others. I later went to work for them (Chrysler) for about a year, driving cars like the Viper (it would beat you up and leave you sore with ringing in your ears from the V10 exhaust being so loud). With the Viper, they appreciated 'rigorous' testing. Thus you were thrown around in the cockpit. after 8 hours, it paid its toll. You didnt want to drive that beast more then one day in a row... (They had different tests for it that needed accellerations, decellerations, turns, etc, which could get violent).
Bill