It would surely depend on what you were trying to claim under warranty? If you require a new fuel injector then I can't imagine your splitter would have any affect on that claim. However if you were to claim for damaged paintwork on your bumper then yes it may cause issues.
Yeah I read something like that it only voids the warranty on the modification you make it too like if you change your wheels it would void your suspension and if you mapped your corsa your engine would be voided etc cheers for the post people.
It's all crap the warranty system mate any dealer will turn a blind eye to whatever you do because they get full pay for every job carried out, my Corsa D 62 plate was lowered, different alloys, retrofitted adaptions like cruise control and tpms etc and everything was still done warranty had a new engine just before I part exd it