Here's some better pictures, be gentle
I went a bit mad with the side of the chassis here, I could have left more on the vertical part of the tub and still had clearance for the motor.
A bit more chassis left here.
T-plate, the wishbones are as low as possible, level with the bottom of the chassis at the back.
Lined up against a standard B4 (bottom), both chassis are level with each other. The mid car (top) is actually slightly shorter.
There's a lot of tidying up to do, especially stuff like how the gearbox ties into the top deck and the rear shock tower mount. The cut down u-brace for the rear toplinks will be carbon fibre eventually, and I'd like to mount the gearbox lower into the t-plate too.
If it works well I'm going to make a full double deck chassis using the GT2 truck front end, there will also be enough room for the radio gear on the chassis. As it is currently with the bracing ribs of the chassis I think I'm going to have to dump either the speedo or reciever on the top deck.