Welcome from England! Wife and I took a train vacation there a few years back right after graduating from college and we can't wait to go back. We'll bring an umbrella next time though - it rained almost the whole time we were there!
Anyways, regarding your delight with the diesel engine, let me be the first to give you a warm JKOwners salute
I guess envy overrules international courtesy when talking a diesel for the JK!
Regarding the license plate location - I agree the European location is horrid. Why not get a new rear bumper to match your new front bumper and mount it there? Or mount it to the rear tire. The US mount is better than the European mount, but it still sticks out on the side and is vulnerable to being hit by a branch or whatever on the trail. Be sure to post up some pics with your new bumper(s) installed!
07 Jeep Green Rubi Unlimited, auto
Mods: Tuffy Cubby Storage Cover, Rugged Ridge grab handles, Shrockworks Sliders, Rock Hard Engine / Gas Tank Skids, Rhino-lined tub, Kilby Evap Can Relocation Kit, 16x8 Centerline Wilderness Series - Falcon Rims, 285/75/16 Interco SSRs, OME 2" HD Lift, PSC Diff Covers, Superwinch EPi 9.0, BulldogFab Rear Bumper, RedrockFab Front Bumper and skid