Nadvys--That bolt is a real bugger. I took a metric (Taiwan) metric wrench and flattened the box end and bent the wrench (spanner) to a right angle. I then glued the nut into the box with the washer and the operation went slick after that. The time was spent in thinking about it and modifying the wrench. PaulJ said he was able to reach up somehow from under the car. Good Luck
A little trick I use when I have to hold a nut into a tight place, don't go there guys, I know what you're all thinking, I put a piece of masking tape on the outside of the open or box end of the wrench and just push the nut into the wrench and the tape holds the nut in place long enough to get the bolt started, usually that is.
If I need to do something with a washer, like to add it to the underside of the nut, I use a bit of heavy grease and it will stick to the nut long enough again to get them in place.
I also have a large selection of wrenches that I've heated with the torch and bent for so many different applications. I keep odd brand wrenches around just for that purpose.
It sounds like we have several with the kits about ready to road test. I enjoy reading all the testing and installation bits and pieces.
You guys all have a great weekend.