Cutting a very long story short I fitted a two channel Thinkware F770 the day after I picked up my car from the dealer, which took about three hours to fit. The Thinkware F770 seems to be the best value dash cam at present based on the numerous reviews and comparisons that I've researched to date. While it is easy to set up the running wires through the car is not easy. That stated I have managed to conceal all but about 100mm of the wires leading to the front dash cam and about 50mm leading to the rear dash cam.
The rear dash cam cable threads through the rear tailgate via the righthand side rubber conduit into the headlining and then along the edge of the driver's side roof and comes out at the top righthand corner of the windscreen. This task requires threading the cable around the driver's side B pillar and again around the top of the A driver's side A pillar - I did this by threading a wire from the windscreen under the headlining and then pulling through the wire for the rear camera and the power cable for the front camera. The power wire follows the same route shown at the start of the thread.
For information:
(a) the headlining seems to be held in place around the edges of the roof by the rubber weather strips around the door, which can be eased back in the car to allow access to the headlining.
(b) do not underestimate the challenge pulling, etc. the dash cam wire through the rubber conduit connecting etc tail gate to the roof panel.
(c) The top plastic cowel around the inside of the tailgate does not have to be removed fully - you can just pull away the top bit which will then drop down under gravity to allow you to feed the wires through the tailgate door etc. (for a £50k plus car the cowel is pretty cheap and nasty and does not fit very well even before you touch it - my only criticism of the Macan thus far).
(d) you'll need a about 0.5m length of fibre glass fishing, or tent, pole to help feed and direct your dash cam wires through the headlining. Plus, it is also worth buying a set of car upholstery shim tools for a couple of quite off eBay) to help ease panels, rubber conduits, etc.
(e) I temporarily hardwired the dash cam into the car using the UK driver's side fusebox using the following fuse ports in Column B:12 - for the accessory cable; 5 - battery cable. Once fitted the both dash cams work really well both the when the car ignition is of and on. I need to do a bit more research just to make sure that there are appropriate fuse ports
(f) I positioned the rear cam near the top of the tailgate just inside the top arc of the read windscreen wiper. I positioned the front camera on the drivers side of the windscreen immediately to the right console that supports the rear view mirror such that the top of the mirror just misses the bottom of the camera. This places the camera out of the normal driving angle of vision and allows me to operate the camera manually y more easily should I want to do so compared with trying to hide the dash cam behind the rear view mirror.
(g) the rear camera is very hard to see (even with plain glass) from the outside as it is under the rear spoiler. The front camera can be seen if one knows what to look.
Sorry about:
(h) not taking any photos of my work but I did not want a record of any expensive screw-ups, which is a pity given that it all worked out rather well.
(i) the length of the note because I wanted to fill in bits of detail missing from other posts and from YouTube!