How about 4 top quality flush fitting reversing sensors for £135 + P&P ???
Easy to fit (1 or 2 hours max)
drill 4 * 22mm in your rear bumper, thread the wire through.....connect to control box connect to reversing light attach speaker to underneath of rear parcel shelf........bingo.......
could be the bargain of the century..........
Those of you wary of fitting
interested ? email me at prolexuk at ao'ell dot com