After seeing some video's of the DF03 on track and also from feedback here on the forum and from Jimmy's review, I found the DF03 looks jitterisch driving out of corners. A longer wheelbase gives more stability.
Making a longer driveshaft isn't doo difficult if you can use a lathe. But I also noticed that the driveshaft ends of my Hopup shaft from Yeah Racing are attached with pins. So all I have to do is push out the pins, remove the ends and find some alumiunium tube of the correct diameter and I can make any driveshaft length I want.