Hi Andy,
I don't know the definitive answer to this, but the thermotronic option isn't just a head unit in the dashboard. It also incorporates a dew sensor and a solar sensor (which I believe is on top of the dashboard) and an additional vent also on top of the dashboard. I think these parts would also have to be installed/replaced to perform the upgrade.
To be honest, although I went for the upgrade it was mainly for aesthetic reasons - I just preferred it to the look of four separate rotary knobs. I doubt that the system makes a huge difference in practice, so I'm surprised you feel you want to make the upgrade at this point.
That said, for the last 2000 miles I have just left the air circulation on auto and have never had to manually direct the air in the car, so maybe it does do something useful.
Hopefully somebody else on the forum can provide a more definitive answer for you.
I don't know the definitive answer to this, but the thermotronic option isn't just a head unit in the dashboard. It also incorporates a dew sensor and a solar sensor (which I believe is on top of the dashboard) and an additional vent also on top of the dashboard. I think these parts would also have to be installed/replaced to perform the upgrade.
To be honest, although I went for the upgrade it was mainly for aesthetic reasons - I just preferred it to the look of four separate rotary knobs. I doubt that the system makes a huge difference in practice, so I'm surprised you feel you want to make the upgrade at this point.
That said, for the last 2000 miles I have just left the air circulation on auto and have never had to manually direct the air in the car, so maybe it does do something useful.
Hopefully somebody else on the forum can provide a more definitive answer for you.