2. IMO, no as its quite obvious that OE
don't last, were never any good and can't believe Renault get away with the number of
replacements people need on such a critical item. Its appalling the amount of failures people experience. They should be hanging their head in shame and giving them out free. It must be a huge cash generator for them. How much worse can anybody elses be? If buying a non OE part I always try to stick to brands I know i.e. lucas, Bosch etc...
3. There should be no need to change the plugs. Most garages just fit the
and away you go. It you have the time, I don't think there is any harm in giving the plugs a look whilst your in there, but its not necessary.
My father in law does very little mileage and before his car had done 12000miles from new all the
failed (out of warranty) one by one within a short time period of each other. He's recently had to replace a relacement which has only been in around 2 years and less than 8000 miles.
It would certainly put me off a petrol engine that uses these
. My local garage (not a Renault dealer) actually keeps the
in stock as they replace that many of them. It takes them only a few minutes to change a