So I installed the rearguard protector and also the sill protectors.
The rearguard protector was actually very easy to install. Just need to make sure you line it up correctly and use some masking tape to mark the bits either side before exposing the tape to properly stick it down. I was sceptical if the black would go or not but given the bit below is also black and of a similar material it blends in very well especially against the grey paintwork.
The sill protectors were a bit more fiddly to install. It took me a couple of attempts to get it right having to take a couple of them off and put them on again but now they're all on I'm very happy with the way they look. The also seem to offer more protection than the silver strips.
Pics below.