From what I recall, the headrests on my former '09 Caliber SXT (cloth interior) were less comfortable than those in my current '09 Caliber SRT-4 (leather interior). I believe neither car had/has active heat restraints.
The gearing seems to differ between makes and models, also. My Caliber SRT-4 turbo is a 6-speed manual; my previous Caliber SXT was a 5-speed manual, so I expected that difference. However, my low-mileage '89 Caravan turbo (admittedly, 20 years older) also has a 5-speed manual, and the most economic shift points between the two differed significantly. For that matter, I traded my '89 Fifth Avenue recently to a close friend for his '72 Imperial, so his '87 LeBaron GTS (formerly my car) is at my house temporarily. The GTS also is a turbo 5-speed manual, and it shifts differently than the others. I'm a "cheapskate," so rarely do I open the turbo on either my Caravan or Caliber SRT-4. When I drive the SRT-4 on the highway in 6th gear with the speed control engaged at 60 MPH (in light traffic and good weather), I've achieved mileage in the range of 33 to 37 MPG per its EVIC.
One of my two oddest experiences was with my former '65 300 Sport convertible, 383 with factory 3-speed column manual. That car had little pickup until I reached top (3rd) gear — then the car really took off without further shifting. Not relevant to this subject, but I sold the 300 to the same friend with whom I made the Fifth Avenue/Imperial trade. Friends are terrific!
I encountered another strange vehicle on one of my earliest jobs as a clerk for International Harvester; I used IH Travelalls (I believe Yugo owners had better-built vehicles). Most were automatics, but one of the Travelalls (with low mileage) with a 3-speed column manual had such a poor transmission/clutch that I could shift without using the clutch at all (and didn't clash gears!).
