An accident protection must be failsafe. Using a wireless connection is a source of errors. Using a standard Matlab running under an operating system is a source of problems also: What happens if the car needs a decision and the OS thinks it is time for some updates and defragmenting the disk?
Even if you want a test application only, it is necessary from a scientific point of view to consider the fundamental basics. Look for terms like "real-time OS" and "embedded system".