My understanding is that EU rules require a 2 year warranty .. not 12mths .. and the warranty rests with the seller .. not the manufacturer.
(so your TV at 18mths is still under warranty despite what they might claim).
Outside of that however, there is also a requirement that:
Directive 1999/44/EC (Directive on certain aspects of the sale of consumer goods and associated guarantees) states in Article 2 that "The seller must deliver goods to the consumer which are in conformity with the contract of sale."
show the quality and performance which are normal in goods of the same type and which the consumer can reasonably expect, given the nature of the goods and taking into account any public statement of the specific characteristics of the goods made about them by the seller, the producer or his representative, particular in advertising or on labeling."
To me that means any decision (by a court) would likely be based around what is normal expectancy.
If all car dashes have problems and generally last only four, five or six years then that would be the expected normal lifetime.
But if car dashes normally last well in excess of that and in many cases the vehicles lifetime then ...........
So Renault appear to me to be taking a calculated gamble to minimise their dealer's potential losses.
They provide the parts, the dealer gets paid labour by the punter.
Dealer stays happy with Renault.
maybe, just maybe, Renaults reaction is more to do with keeping their dealer network happy rather than the consumer ......