First, some background...
On making extensive enquiries and visits from a local Installer I was told the following:
a. You can't fit FRONT Sensors due to the low height of the front bumper!
b. In order to lead cables to the rear... You have to be able to remove the s/steel 'scuff-plate' then the plastic moulding at the front and rear with a 99% likleyhood of un-repairable damage!
c. You can't fit REAR Sensors due to a 'metal plate' inside of the bumper!
Obviously he didn't want the job...

The Front bumper 'outer' sensors are at a road-height of 48cm but the 'inner' are only at 44 cm. But the problem here is that the actual curvature of the 'early-model' bumpers is not wide enough to take any Sensors but, YOU CAN fit the (2) Outers! The REAR Sensors are all at a road height of 48 cm. (I understand that manufacturers recommend a road height of 40-70 cm is ideal.) and there is NO metal plate inside the Rear bumper 'it's plastic!

Using a large plastic trim-tool it's possible to lift-up the scuff-plate enough to lay any cables underneath and lead them inside the window edge moulding, through the plastic to the rear of the vehicle. No problem.

So in the end.... what did I get fitted....

Using a professional installer located in Fareham, Hampshire, UK I had (4) 'CISCO' Sensors (correct colour coded) fitted into the REAR Bumper (without its removal) together with a 'audible' alarm behind the rear seat and it works perfectly. Took a couple of hours to do.

Can supply contact details.....

pp. Seeing that it is actually possible to fit FRONT sensors (2 only) with a dash switch to operate, I may have this done later.

Its also possible to lead any cables from the front of the vehicle to the rear by using 'removal of the centre console' (you can do this yourself beforehand or get the installer to do so... Its an extra hr labour.