This may seem a daft question but will fitting any/some of the following effect the std 3 year Subaru warranty
1/.17" wheels and tyres
2/.K&N panel filter
3/.Scooby sport back box
4/.strut brace
any constructive comments welcome

I would say no,

The K&N would have to be proven to have cause the failure resulting in a warranty claim, as with any of the other bits, which would be highly unlikely. Generally it is the bigger mods which will upset them :D

The SS backbox should be ok, as Prodrive do a similar type of thing for the upgrade, slightly quieter :)

MB

To be on the safe side I'd get a letter from Subaru confirming they will honour any warranty claims if you fit these items. Subaru locally state that ANY non standard Subaru parts could/will invalidate your warranty - technically even a Subaru boost gauge on a WRX, never mind non Subaru parts.

Thanks, I will follow this advice.

The only problem you may have is if Subaru believe the K&N filter oil stuffed the MAF sensor, apart from that there should be no problems with that