If you are considering fitting one of the BMW kits, then save yourself about £250 and fit one like this (a 4 sensor Brees make).

Parts List (approx prices):
1 x 4 sensor (20mm hole type) PDC kit Brees or similar - Ebay - £40.00. (See Below)
2 x 20mm Black PVC Conduit Couplings - B&Q - £2.00.
3 x BMW PDC Bumper Strips - Dealer - £43.00. grrrr . Part nos: 51128206375, 51128206371, 51128206372.
Small cable ties, glue, PVC tape, 2 x M6 nuts and bolts.

Tools:
Dremmel/Drill
Screwdrivers
Wire cutters/pliers
Soldering Iron

Here we go then:

This shows one of the sensors, make sure they are the 20mm diameter hole type, as these can be recessed into the BMW strips and are a good fit into the couplings. And the 2 x 20mm black PVC conduit couplings.

Here's the coupling trick :
The couplings are used as spacer sleeves for the sensors, as the BMW holes are 22mm diameter. They fit tightly into the strips - very hard push

Allow approx 4mm of space at the front edge to allow each sensor head to fit neatly recessed, as per BMW OEM.

Cut off the coupling to about 10-15mm length, then push and twist each sensor into the coupling from the front. They are again very tight fit, very careful use of pliers may help here. To be doubly sure of a fixing, although I think this may not be necessary, use a bit of hot melt or superglue at the back.

The sensor should now fit tightly recessed into the strip, all as per BMW OEM sensors (at £53 a pair ).

Now remove the back bumper and unclip the non-PDC Strips. On later models the bumper skin is pre drilled for the sensors. The bumper support still needs to be Dremmelled out a little to fit the depth of each sensor.

Each strip with sensors and cables attached should now clip into the bumper, feed the wires neatly through and they will push neatly into the polystyrene backing. Push fit the wires along to the LHS of the bumper (over the exhaust!). Cable tie them at this corner.

Offer the bumper back to the car, pass the cables through the LHS rubber vent. Make sure they are tight up here and away from the exhaust heatshields. Bolt the bumper back on.

The PDC Control Unit can be mounted with the M6 bolts now, to the frame under carpet in the boot, over the rear passenger side wheel arch. All as per the BMW OEM install. I was lucky and the pre-drilled holes lined up .

Now for the wiring:
The 4 wires from the sensors simply plug into the control unit, make sure you get them in the right order (they were labelled A to D). The power cable (red) take to the rear light cluster and solder onto the reversing light feed (blue/yellow cable), the black to ground (brown on the cluster or the earthing point over the back wheel arch in the pic).
The wire to the display/bleeper I took to the dash (it is 7 metres long!), following the original wiring loom behind the passenger rear seat bolster, under the passenger side carpet cable covering, behind the glove box then out to the oddments tray.
Neatly tie all the cables in place, make a better job than me...LOL.

Pics of the sensors fitted .

I have wired the display to the oddments tray, temporarily.
Later I will post up PART 2, how to fix the display into the OBC/clock frame along with a Digital Clock I acquired from a Compact, as an alternative to the OBC option.

Now I think I deserve that pint.

Anyone attempting this is as mad as me, so if you get stuck then ASK!

Written by JohnW on e36coupe.com. Original post can be viewed here

Baker Leisure Services Sell the Brees kit pictured below (this may be who JohnW bought his from as they do sell them on ebay).