So, after being inspired by the Edge Speaker fitment thread on here I decide to go ahead and upgrade the Duster's sound system.
I opted for a set of 4 Pioneer 3-way triaxial units: http://www.pioneer-car.eu/eur/products/ts-a1333i
The fronts go in without issue but the rears have a clearance...
Duster Laureate purchased in March 2014 with most conceivable available extras made for a lovely good value car. Extras included;
Touchscreen media nav
Cruise control - not standard when I ordered it
Rear Bumper protection
Wheel arch and door protection