Dash cam advice please

[kawashima]

I recently bought a dash cam for my car(for the first time).
It has 2 modes, one is always recording mode and one is event mode (before 10sec and after 20sec of impact).
And it has GPS and G sensor, when I play on my PC, it has speed meter(km/h), G meter and google map.
I'm using it in always recording mode now.
Basically I drive safely but usually don't keep the speed limit (+20km/h on safe empty road).
Now I have two questions.
(1)when I have some accident with other car, police comes, and can they take SD card off from my dash cam for investigation without my permission? (in U.K. case)
(2)Will I be punished for speeding in the past if they see all movies?
(in U.K. case)
If so, how do they drive with dash cam? Do they always have to drive within speed limit? Or an "Event mode" is for such purpose? Do some of you have dash cam in your car?
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own:2020 Serow 250
owned: 2012 YB125SP, 2008 TDM900, 2005 W650, 2002 LS125R, 2002 CB400SF, NS50F, C50 / Trip to UK(2009), Hokkaido touring(2013)

[Im-a-Ridah]

1. Yes, they can take any evidence they like.
2. Possibly? But it's not an approved measuring device so you'd have a good chance if you fought it. If they can't get speeding, they might still be able to get driving without due care, careless or even dangerous driving.

[iooi]

Just remember that event mode will leave temp files that are viewable. It will simply overwrite the files. So how much is there, depends on card size.
If you want to speed and only really have it to record the 30 secs, then you need to find out how much space this is and get a card that is not much bigger than this.

So in effect make no diffrence to always on mode.

You could just mount the cam where its not easily viewable, and you only roll it out in the event of a accident to show the bits you want seen.
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Just because my bike was A DIVVY, does not mean i am......

[kawashima]