MY00, std back box is looking a bit worse for wear with lots of rust, although no holes just yet, if it were to develop a hole before the 3 year warranty expires (October 2003) can I get it replaced ? also the battery won't stay charged if the car is left for more than about 4 days with the alarm on (not in shutdown mode), would I also have a case for getting the battery changed as well, or will they tell me to put into shutdown mode I I'm leaving the car for more than a weekend ?

So long as still in manufacturers warranty and mileage below 60k, you will be able to get both exhaust box and battery replaced,so get to your local dealer before it runs out