I can't speak for OP, but I had the same problem in my last flight just now. Apart from the van thing, I also had that when I loaded into FKKD, I was getting big fps fluctuations around 40 fps (so to ~50 fps, then ~40 fps, then back to 50 etc. all very rapidly). Then I went into settings, selected maximum buildings instead of high, waited for XP to load, then selected high buildings again and I got constant 60 fps after that. This seems to be similar, where an object somewhere causes (only in the CL650, I didn't get these autogen related stutters with any other aircraft) the fps to go to 40 and oscillate constantly +- 10 fps. I've attached my log.
As a workaround for now I just reload my scenery each time these stutters happen, but a more permanent fix would be nice!
Best wishes!
Log.txt