a turbo issue is different , there is a lot of problems with turbos right across the board, ie all manuafacturers, and thats a mechanical problem you couldnt foresee, but then having said that there is a correct way to look after a turbo car. you cant really prevent that sort of failure, you can prevent other things like your bonnet not being shut!!!
There you go again... "there is a correct way to look after a
car". So, I presume that, like some other Renault mechanics before you, you think it is down to the owners.
As a mechanic working for Renault, you must have come in contact with a few worried owners who actually had to pay a lot of dosh to your employers (dealerships) because these did not exactly volunteer the information they had that the 1.9 turbos were failing left, right and centre, and that the option existed to apply for Yellow OTS support. Why would they? If they charge the client they get upwards of a grand but if they charge Renault they will do it for a pittance since the mother company does not pay its dealership £100 per hour plus VAT for warranty work or other commitments either.
Since you reiterate that "you can prevent other things like your bonnet not being shut", I hazard to ask again, "How do YOU check that the safety hook has engaged when it is neither visible nor accessible?" You are the mechanic, so explain it to me, please.