My feeling is that it wouldn't as they are serviceable items and as long as they are of equivalent quality, supported by a valid receipt, there's no reason why there should be an issue.

Any definitive advice please?

Nothing definitive, but I would tend to agree.

There is a but (well but's actually) though, how much longer doe the manufacturers warranty have to go?. Also, how much cheaper will it be to get the brakes one elsewhere?

I suspect any failure of any part of the braking system they could try to deny warranty due to non OE friction materials getting the blame for the failure, ie if the ABS module failed...which on some cars are frankly ridiculous prices as the current Honda thread has shown...there's bound to be some small print about parts.

In practice i don't think that would happen, it should be possible to buy genuine parts online or very similar if not identical items from the same brake maker who supplies the car manufacturer, in which case its doubtful anyone would even notice the difference...ie Textar pads could be found on some German cars, same part numbers but come in a Textar box instead of a box with the car makers name but at less than half the cost, i know this as fact because i've done the swap with the car still under approved used warranty and saved the family owner a lot of cash.

I'd try and get the same makeparts as the car maker fits if possible, so in the event of caliper or other failure in the next 2 or 3 years when the mechanic removes the pads if he casts his eyes over the pads they are at least the same make as would have been fitted by dealer workshops.

Thanks that all makes perfect sense to me. Car is an Audi Q5.