not a recommendation per se, just sharing my experience.
resolution: i saw a garmin 45 on sale one day and grabbed it. it works perfectly well but if i had to buy one again, i would get as high a resolution as possible. mine is 1080p and it's nearly impossible to see license plate details. the image is great, but due to the wide angle, a license plate doesn't get many pixels.
mounting: a little hexagonal disk adheres to the windshield and the dash cam has a magnetic mount that swivels. you have to adjust it when you put it back but that's easy. mine has a mini-usb plug and since i have the cable as tucked away as possible, it is very short. it's not a game changer but if i had to swap it between cars, it would get old fast. i don't know if any cameras have any kind of plug that connects when you stick the camera on but that would be nice.
i think most cameras keep recording over old images. i just put in a 64GB card and it holds weeks of recordings. newest recordings overwrite the oldest ad infinitum.
mine also has gps which it uses for speed and time stamping the videos. not sure if that's a good thing or not since it could be self incriminating. i don't think the location data is embedded though.
the garmin also has collision warning and a few other gimmicks but i've got them all turned off.
hope that helps a bit. feel free to give me a call if you have any questions.
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MY 2000 S, Ocean Blue, Metropol Blue, Savanah Beige.
Bought June 2000 - Sold May 2010