Custom automotive electronic design, manufacture. Can-bus

After scouring local and web sources for someone to do the job, I figure maybe posting here will bring someone to me. We need an electronic cruise control developed for a specific car (German make, new model, Can-bus). Ideally looking for a firm that can take us through-to-market complete from concept, to design, to prototype, to testing, to component sourcing and production... but would accept concept/design/proto/testing and I'll handle production elsewhere if necessary. One car will be provided. It will be expected that you have experience and equipment to rapidly investigate the car's protocols with little or no documentation, determine what does what, and come up with a functioning cruise control device that interacts with the car's computer in a safe and expected manner - that is, it behaves as one would expect a cruise control to behave. The car is drive-by-wire... there is no mechanical throttle body like a typical car, so the accelerator pedal is simply a fancy switch... ie. no cable physically controls the throttle so there is no need for servo, etc - 100% electronic. Background: In previous years, a German company has been supplying us with this aftermarket cruise control. The car manufacturer has changed the model for 2008 and the existing cruise control will no longer work. Rather than wait for our German supplier to come up with a new design, I would like to be the first to market and make some improvements in the meantime. So I know it can be done (they did it), but I don't know how to do it. You have the know-how, I want to hear from you. Please only bid if you are confident you can do this. If you've never worked with automotive CAN-BUS you probably aren't a candidate. If you don't have the equipment to analyze a CAN-BUS from scratch, you probably aren't a candidate. If you don't think you can keep cost and practicality in mind - you are NOT a candidate. You are bidding on investigating, testing, designing, and proto-typing a functioning unit to our criteria. Thank you.