Wow this thread just bought back some memories.
I was driving my mom's 08 WK 3.7L on the highway at about 75mph. My friend knocked the shifter and put it in manual shift mode. I wanted to put it back in normal drive mode and I thought the proper way to do this was to put it in neutral then back in drive.
Rather than going into the proper gear when I put it back into drive from neutral it shifted into 1st
The tach instantly pegged all the way to the right and it felt like I slammed on the brakes. The engine basically exploded under the stress. Needless to say I had to have it towed.
It ended up being that when the engine overspeeded the rocker arm let loose and whacked the valve cover. The cam lobe was pretty much a mess too and the casting was cracked where the push rod / lifter was.
It was all covered under warranty. Apparently it was a known software bug.
Long story short never go manual-N-D. Actually it's probably fine to do on the new wk2s since I'm sure they fixed the issue but I'm not going to try it. The Jeep has been perfectly fine since they fixed it. My friend is no longer allowed to sit in the front seat.