Ace I've done hardware and software and agree this is not a trivial task. There is never 100 percent reliability. If you have two pieces in system and they are 99 percent reliable the assembly is only 98 percent. Also for critical sensors there would need to be redundancy which would add cost. Also how would the software be updated. One more thing there would have to be some standardization for the code for each auto maker you really don't want multiple versions of code.
Finally you want safer cars get the bad drivers off the road. Yeah there still will be accidents but hopefully fewer.