For £200, I would buy:
3x Mobius C2 (£155 - Spytec fulfilled by Amazon)
1x Mobius capacitor conversion (£5)
2x suction cup mount (£10)
1x adhesive-pad mount (£5)
3x 4m length of USB-to-miniUSB cable (£10)
1x twin- lighter adapter (£5)
2x 12v-to-USB adapters with 2x 1A sockets on each (£10)
Total: £200
That gives two cams for the front, in case one fails. Plus one cam for the rear where sometimes events start unfolding outside the view of the front cam.
Use the adhesive mount in the rear window and the two suction cups in the front window (or use adhesive in the front if more suitable).
Fit the capacitor-converted Mobius in the front, with the others in front and rear windows.
What's in my car?
JooVuu X front and rear, plus Street Guardian SGZC12RC front (can't fit SG9665GC due to big mirror housing on windscreen). You're talking about £350 for that setup though.
I also retain a Mio Mivue 538 in the front because I sometimes like to be able to check how fast or slow I was going and I like its media player which has the GPS map plot which makes it easy for me to search for something that happened at a certain location. I also often have other cams for experiments and for various reasons sometimes change my cams (although the SG-RC is stuck so that doesn't change).
What's in my wife's car (her choice with some guidance from me)?
Mobius C2 front and rear, plus Transcend DP100 front.