CA Automotive approached me back around July/August last year as they work closely with ESS and knew they were looking for a development car. They offered me the chance to submit my car in return for the work being done at half the price.
I didn't take them up on it for a number of reasons (car having to go to Germany for a month, i didn't want to risk warranty - and also I couldn't afford it - half price was still £3000 (or $6000)!).
I didn't quiz them on power outputs at the start, assuming it would push power to 420-440bhp, but at a show towards the end of the year I had another chat with them and they told me they expected power to be around the 520-540bhp mark!
It certainly sounded very good at that point, but still wasn't something I wanted to do on the car at that point, even if there would be a certain kudos for having the first one.
I don't think development will take very long. Like I say, they quoted 3-4 weeks, and as I understand it, it's mostly just repackaging the E46 kit into the Z4M bay (which has a LOT more room), and adapting the map for the new software on our ECUs. The rest is already proven.