You would wonder how much software of parts in your Tesla is written by this big bad german car suppliers that all work under the MISRA rules.
Would the critical software things of a Tesla be written by Tesla with their quality understanding, then this cars would be just death traps.
Hmm, what do you mean? I think this is mostly public knowledge. I don't know how much Tesla tries to inhouse, but I would guess it's roughly similar to other OEMs (kinda a wild guess tho)
Most of the components are designed by suppliers they partner with. I don't know that you're going to find a good hyperlink for this stuff.