Yeah better safe than sorry, not least in this age where the means to be safe dont cost you a fortune.
I use to have a CCTV camera ( IP camera ) on where my car are parked in the back yard, i simply had to as after moving here i saw several cases of vandalism towards my property / cars.
First i had my SUV keyed all along one side, a few days before i was to sell it, so i had to take a additional loss, then i got my little red car and it was barely a year old before it had the passenger side window broken ( nothing stolen )
So i then decided to park in the back yard, but then parked there some A-hole had thrown a D cell battery high in the air, and it came down at the back L corner of my roof making a dent there.
So i got myself a NVR and a few cameras, and then nothing happened.
Now,,,,, okay a while ago the PTZ camera i had on my car broke, and i have not gotten around to replacing it, they are pretty expensive for a Danish pension, and its been years since i blew thru my savings i had from the sale of my house / the SUV which i also got a little cash out off, and some other funds coming my way.
So now if i flip pennies i can save like 1-200 USD every month, and then usually when i have gotten a little piles something unforeseen happen which cost that pile of money or maybe even a bit more.
Or if i have been really lucky i have managed to get a little money in and get something nice for myself, and then something happen in a few days or weeks, like a few months ago where a root canal suddenly became a must have, right after i spent 1000 USD on myself.
Regarding external cameras i only thing street guardian and viofo offer that option for some of their models, maybe blackvue and thinkware too.
Personally external cameras make me a bit apprehensive, regarding dirt accumulating on them ( a issue i think for camera detail in dashcams, not so much a issue for a low resolution reversing camera )
And maybe scratches on the lens / housing glass from repeated car wash.
So happy my stupid little 5 door hatch back have a vertical rear window and a wiper on it too,,,,,,, though i do need to buy new blades front & rear for the car too.
And if you like to share footage, of funny stuff or insane stuff which all happen far too often on our roads, well in that case you cant have too many cameras in the car.
Our good buddy
@SawMaster drive a van too, but as i recall his is a older one with glass in the back doors, but other than that he is probably the van expert around here.