have noticed that i have 2 cracks, quite big too, that run nearly the length of the spoiler on both sides roughly in line with the rear light cluster, probably the previous owner(/s) using it as a bootlid handle (grr!) on the underside of the spoiler, what are my options on trying to fix it?

its a official prodrive spoiler, at least it is as far as i know, i would assume its a official one as i have the PPP certificate that came with my RB5.

 

I've seen a fair few RB5 spoilers like that. I would guess at a body shop being able to plastic weld it though.