One thing to add to the X6 squared comments, is that I find that there are other things I like about it other than the car. Most peaple have to make a few mods themselves to the car, such as fitting the rear sway bar and removal of the battery sections on the chassis to fit saddles. I don't mind having a play with that sort of stuff but you need to be prepared to have a go! Also, I think it is still a 'work in progress' to some extent, there is a new rear shock tower / bulk head being tested at the moment that will move the rear wing forward over the chassis.
But in the main the there is a basic set up for the X6 and there is not too much deviation from it. for example I have only ever flipped the hangers over on the back end and swapped the pink for the red springs as a mod - across the indoor and outdoor seasons.
I am now running the inline axles again and have removed the servo saver which has made the car more responsive. I am a bit more use to it now, though.
Weight and e-speed hangers both seem to make ther car better. I had about 170 / 180 grams in the car yersterday and some may say that is on the light side.
this does look interesting though, another tight fit I think!
http://www.cmldistribution.co.uk/news.php?view=0000001740