First, a minor point - there are no 12v sources in the 2021+ S/X, as they are 16v (usually around 15.7v). This means those 12v LED strips will run a bit hot and may fail over time. If you use a controller, you can dim the brightness a bit and I expect you'll be ok. If the LEDs are specifically designed for cars, then they are meant to run at 13.5v or so - typical in older cars with Lead-acid batteries. Still, everyone calls the 16v system 12v for convenience - just be aware it's not 12v.
I made an extensive list and tested each for power capability and when they turn on and off. This includes the latest S/X/3/Y as well as some of the older models back to 2016. Different models work differently. Here are the details:
Accessory Power Guide 12v/5v – TeslaTap
For my 2022 Model S I use the power from the phone charger for my LED lighting. In my design, I use 5V addressable LEDs, so I use a DC-DC inverter to get the 5V I need. The phone charger is very easy to access (no screws) and it has relatively high power (at least 2 amps). Here's how to make a tap along with all the connector information.
Power Tap – TeslaTap