We are not saying it is totally down to the Renault's fallible design or manufacturing approach for the catch mechanism (both catches that is!), but it is also down to the maintenance process too.
Many (if not the majority) of vehicle owner's don't envisage the need to maintain the bonnet catch mechanism (in the same way as checking the
/ tyre pressure etc) - and many assume that this is also done during routine servicing (major / minor). Apparently, we have identified that Renault do NOT mandate the servicing - so it's simply "pot-luck" whethe the bonnet catch is actually "looked at", yet alone cleaned and lubricated during servicing by Renault.
Back to your other point about a bonnet should stay close at all speeds - "if closed properly". Actually, the fact speaks for themselves. In th majority (if not all) of the reported cases, the mechanism has "released itself" without any intervention. You can safely state that maybe in 1-2 odd occassions, the driver didn't close the bonnet properly - and maybe it was on safety only. But all 1000+ cases? Can you honestly state this without any doubt whatsoever. Well this is the exact position we have posed to Renault and VOSA - and neither can prove that it is down to the last person who closed the bonnet (i.e. didn't close it properly). There is no TECHNICAL or OPERATIONAL evidence which they can use to confirm this.
All we have is facts, the main catch can only be released by pulling the release lever from the passenger's compartment. (Regardless whether the safety catch is "engaged" or not). So what has made the main catch release itself - possibly a bump in the road, maybe a gush of wind, but the catch is meant to be designed to cope with these types of "normal driving conditions". What makes it worse is that in the slim case the main catch does release, the safety catch should always been in an "engaged" position, what we have proved (VOSA and Renault now concur) is that there is a chance that the safety catch is stuck in the released position - meaning it's defunct in these circumstances. Doesn't this therefore sound like a flaw in the mechanism functionality - oh yes this means "design" or "construction" of it?
Can you see our point though?
I value your thoughts and insights, and am happy to hear that both catches seem fine on your vehicle - and hope that you are taking the responsibility of "maintaining" them - just pls accept the fact that's it is not as obvious as you think - if the bonnet is flush, and you are driving for up to 4 weeks without any signs of something "being wrong"!