I had to get my G25 replaced due to a faulty brake pedal. I would have been happy with just a new pedal set but they don't deal with individual elements of the unit!?
Logitech asked for the plugs, all of them, to be cut and sent to their Switzerland offices. You get a specific RMA number and I was told they need these plugs to close the RMA procedure.
I considered not bothering, as I thought they probably won't chase up. However, I did in the end, because if I have further problems in warranty, I may not get support if it is shown that I didn't return the plugs as asked. It is a £170 unit after all. Their customer support has been excellent, so I think it's right.
I'll try and fix the pedals, plus connect them to a USB device with a bit of wiring up. The old wheel now lacks it's USB connection plug, but USB has standard colour coding, so I should be able to fix an old USB plug to it; gives me a spare wheel. The shifter of course is useless without it's plug. I'll probably just open it up and have a poke around