Thanks to you both for your advice and help so far, greatly appreciated.
I would love to trust my Honda but in the 3 months of ownership i've had the following:
Clutch judder until car has warmed up (dealer can't find fault but has acknowledged the judder)
Air con failed twice (dealer still can't find a fault and just keeps recharging)
Several trim parts fell off or come apart and have had to be fixed (inside and outside)
Washer jets stopped working
Smell of petrol at startup but disappears when car has warmed up
Battery doesn't seem capable/weak
And now this pinking thing
Just to name a few things... this is from a car that's only had 1 previous owner, full Honda service history and has only done 40k miles.
I want to give the Honda a fair trial though so I will see the car out for a couple of years but it's my first Honda and I'm not overly impressed with it at the moment - maybe I was expecting a lot more as most people talk of Honda as being bulletproof but i've never had any of the above kind of problems with any other brand of cars, even Renault or Citroen which often get generalised stick for being unreliable.
I'm hoping the Honda comes good and I'm a believer in the saying 'only time can tell' so fingers crossed