Actually most of them have dual power option...either plug into your power adapter or hardwire. Even if it doesn't have a hardwire option, the cigarette lighter adapter is 12VDC and you could just clip off the adapter end of the wire, put an appropriate fuse size on the positive side and just hardwire it, tucking the wire away behind the headliner and/or dash panels to behind the dash and to the battery or a positive 12VDC location.
As for wireless power (I'm assuming you mean an internal battery in the cam)? I don’t think you'll find many options. A lot of the higher end ones use a good amount of power and in order to keep the form factor small and light (no large battery incorporated into the cam) usually need continuous power. Not to mention, lithium batteries don't survive well in direct sunlight sitting on a dashboard for any length of time. Lay your cellphone on your dashboard for an afternoon in the hot summer months were you live and roll up the windows. You'll probably return to a destroyed device.
I dont think that is an option you should base your purchase decision on. I hate wires hanging down as well and I just hardwired mine directly and hid all the wires.
That being said, I purchased a BlackVue product, the DR900X-2CH. Their stuff is very well made and have great product reviews.
