Just to let the thread contributors know what decisions I took in the end: I bought the HTC Desire HD (and have never looked back, it's great!). I also bought a car holder CU-S440, which does NOT trigger car mode automatically. I also invested in Tasker (5 star app) and programmed it as follows:
- When connected to AC power, start bluetooth and unlock if locked (see below)
- When connected to my car's bluetooth, set variable %CARDOCK
- When variable %CARDOCK is set, load app HTC Car Panel, which triggers car mode and starts Car Dock Home v3 in my case. It waits a few seconds and then starts any other apps that I want running when in the car.
- When power is disconnected, variable %PARKPLACE is set to %LOC, letting me use Navigator to find the car if necessary. Bluetooth is turned off. Variable %CARDOCK is cleared. App Car Mode from the same developer as Car Dock Home v3 is loaded, which reverts what Car Panel did, i.e. it turns off car mode. Car Dock Home v3 is set to terminate when car mode is turned off. Here one can also kill any application no longer needed. Finally I set the display timeout to the desired value, as this seems to be affected by the above for some reason.
To determine the screen's current lock status I set a variable accordingly for the locked/unlocked events. This requires the Widgetlocker app to work.
I played with a number of variations of the above before settling for this solution. The main advantage here is that car mode is only triggered by bluetooth; car mode is not terminated by the loss of bluetooth connection, as this might happen while driving, in my case. This provides for a stable car mode status as long as the engine is running.
I hope this can be of use to someone.