I had a similar thing -- I wanted to get out of powertrain controls software (engine code) and into the much more lucrative, much longer term AV/driver assistance space. I found a position in the research department, interviewed for it, got accepted and then was blocked by my manager (supervisor's supervisor). This was sold as a "we'll look out for opportunities in 6 months" which (surprise surprise) turned into 18 with no hope in sight and a bunch of ugly reorg on the horizon, so I bailed for a different automaker.