Cars are probably a pretty good application. Plenty of power available, good view of sky usually (or in a city with cell reception), and stable platform might help with directional antenna compared to handheld.
More power won't help you here, I think: Since this uses regular terrestrial LTE bands and modems, you wouldn't be allowed to use any more in the uplink than a regular phone (i.e. 250 or so mW EIRP).
I could see in-car based Starlink usage in the Ka band, though – the Starlink Mini terminal definitely fits the form factor and power envelope.
