Have you considered 1 winch in a Carrying/dismountable mount with a Hitch reciever front & back.
Easily fixed & stored safely in the vehicle.
If you are using Synthetic rope for lightness its kept away safer from theft/vandalisim.
Install your electrics to the front & rear
with recovery points that will also be required for recovery or Double pulls.
Just use when required
& no Insurance company problems
As a quick example,
www.devon4x4.com(free postage, not always expensive, deals can be had.
But available from 'Winch Solutions' & many others.
www.goodwinch.comwww.superwinch.comFor Insurance, possibly consider a specialist Company that understand 4x4 & travel needs.
eg
www.premiumchoice.co.ukwww.suretermdirect.comHave fun.
george
PS, we have a Forum member 'In Scotland' supplying very very good winches.
'Growlz'
& someone with recovery gear, see the bottom of my post.