Question about Teltonika Rut950

This router can very well be installed in a car. However, it should be noted that if the router is in the car, the reception via LTE will also be poorer depending on the position of the router in the car. We use an additional antenna that we position according to need and reception. Sometimes behind the windscreen, sometimes outside on the roof or somewhere else. However, the signal strength also depends on the provider/coverage of your SIM card. The antenna cable must not be too long, however, as some signal strength will be lost. Regarding power supply via 12 volts, I refer you to the explanations by "Digibeni".

This is not possible without tinkering. The unit uses a relatively unusual 4-pin plug for the power supply. But actually no problem if you cut the cable of the power supply unit and use it for this purpose. Voltage can be between 9V and 31V, so no problem in the car.

For installation in the car, however, I can also recommend this device from MikroTik: MikroTik LTAP MINI LTE KIT, Dual-SIM Modem.
It is much more compact, robust and has a wider temperature range. You can connect external antennas, but then you have to do some tinkering. Configuration no problem for people who know MikroTik routers (same software), a bit more complicated for newcomers. Power supply via Micro-USB, 12V (can be between 8V and 30V) or via PoE. A super part to install. The built-in antennas are not bad at all. I would only connect external antennas for a fixed installation with a 12dB antenna or similar. (e.g. for a fixed installation in a house where LTE reception is weak), but not in the car. The gain from a better antenna position is lost again due to the loss in the cable.