Just fitted my rear carrier I recently purchased. Took all of 10 minutes to take off the grap rails and fit the carrier.
Yes Mark was a bit expensive, but it is well made. Looked for others but they looked cheap and nasty. You can get the one overseas for around £35 but with shipping and import duty comes out more expensive and you have to wait 4-6 weeks shipping time.I saw these too, very nice but it was £79, a bit steep, so I just have a bag over the back seat, should be able to fix a plte and top box on it no problems.