Current 4K models are lacking a little in low light performance, but this do by no way mean that they are garbage after the sun set.
Those 4K models will log your lane holding according to markings or side of road, and they will also record just fine the color of any light you go thru.
But the already marginal ability of dashcams to capture plates in low light will be less for the 4K cameras than the best low light 1080p sensors like the IMX 291
This don't worry me as i hope to never be the victim of hit and run while driving or parked, and if you are parked you will only stand a chance of a plate capture if its in a well lit place and the speed are very low ( parking lot speed or lower )
Some idiot tearing your mirror off at speed when you are parked curbside, you only stand a chance of capturing if it is on a nice sunny day,,,,,,,,, that's just the limits of dashcams today.
Parking mode in general run off your car battery, with a low voltage discharge protection, but a few brands offer stand alone batteries for this, but i am not sure if all of those can work with any model from street guardian.
As i understand one of the power packs from another brand can be made to work with SG cameras, but better tag the boss
@jokiin in so he can verify
Depending on your vehicle, you can also put a large AGM battery in the car "beside" the factory one, and then put one of those splitters / discharge protectors in camping folks use to insulate their power batteries from the mobilhomes / campers start battery.
In that case the dashcam battery will be charged while you drive, and be isolated so the dashcam can only use that for power.
This is the route i would prefer to go if i was to get a need for long term parking mode.
STILL ! You have to drive some to charge any battery, its no good to only drive 1 hour daily and use parking guard the other 23 hours of the day,,,,,, good thing a car generator do provide a lot of Amps for fast charging.
And fast charging are something that are a bit lagging in the dedicated dashcam power packs, where i think 10 or 12 Amps are the max for some of those batteries.
Where as a AGM battery you can "hit" with any number of amps that are not used on the factory battery, and i think car generators do something like 50 Amps in charge rate.
GPS at least in all SG cameras and many others are a stand alone antenna on a wire, so you can just not plug that in to make absolutely sure, but there are also a few options in the menu yo have things stamped in the footage or not.
In anyway your speed can always be more accurate determined from the video itself, as a result if time spent to cover some distance between 2 things you can go measure the distance in between, this are probably what a court would use as i doubt the consumer grade speed logging are good enough to satisfy the court.
In most cases no one will see your camera if it is mounted as stealthy as possible, so if you play nice with anyone that come up to your window i see no reason for him / her to detect your camera.
And most dashcams have a screen, but it turn off in seconds after start if that is what you set it to,,,, and this is recommended, not wise to have screens going and it also generate more than needed heat for the camera to deal with.