Here I am going to pull you up on your Cars album review
Firstly,
Heartbeat City wasn't an album that pulled them back from the dead.
Candy O, Panorama and
Shake it Up were all huge selling albums and they were already a huge band (just not very popular in the UK though) In fact I can remember buying
Shake it Up when it first came out and it was a huge seller in the USA as had been all their albums been before that. In between the singles from the first album and
Heartbeat City, both "Let's Go" and "Shake it Up" were big sellers. What
Heartbeat City did though, was to break the band as a huge MTV act and they put out some of the slickest videos around at the time. The Heartbeat Music video (a collection of several songs) and their 1984/85 Houston concert got a lot of TV air time and I remember they were the most modern and slickest videos around at the time. The album
Heartbeat City I agree did benefit hugely from Mutt Lange's production, but if you listen to Shake it Up there are signs that they were headed in a more synth direction anyway.
Gradually album by album Benjamin Orr's vocals were on less songs but on
Door to Door he had more songs than normal, maybe because Ric Ocasek was more focused on production duties.