I've installed additional points in both my cars for powering stuff. It's not that hard if you're a little handy with a soldering iron and some trim removal tools
In my car I jacked in a second power socket off the back of the existing one in the dash. You need to be aware of the total power draw to ensure it's not exceeding the total capacity of the circuit, but considering I'm powering a dash cam and a hard mounted phone charger it's all good. The only way I'd be concerned was if you were trying to run a high capacity inverter.
In my Wifes car I added in a separate circuit (mostly because I couldn't get to the back of the existing socket) and have hard wired in the dash cam power as well as a second socket which has one of these inserted:
It all lives in the glove box using the two points on the plug for front seat passengers, one running behind the dash to the drivers hard mounted cradle and a spare cable in the glove box for the passenger.
The extension cable can be pulled out and run into the back seat for the kids.
If you're not comfortable doing it yourself it shouldn't be too expensive to get somone to tap in an additional circuit. What sort of car is it anyway?