i dont have them in my clio (yet) but did have them in my nova. I also had 3 point harnesses to. I put the main bolt (the long one that goes towards the back of the car) in the standard whole that was there for the rear seatbelt buckles to go into. The side two, one went into the standard whole where the bottom of the originall seatbelts went and the other went into the whole where the buckle went. I had small strengthening plates welded in for support, then the eyes just screw in easily.
I got my subframes from the same place that i got the seats, i had proper nova ones not universall. I got them from a place called europa (they do have a website), its just round the cornere from mine.