I was just about to set off down this route myself until I spotted this thread
Have you been able to interact with/set the cruise or speed limiter?
I believe, but I'm not sure, that the airbag system can be triggered by an errant CAN message (unconfirmed) - if you're injecting signals onto a live car, how are you ensuring this doesn't happen and do you know what they are? Would be a right pain to write off your car with a mis-sent message.