The big Q is...........who will be driving the car more you or your mum
If its you.............never ever drive near a blue Audi S4 avant or my Green is200 with me at the wheel, as i dont want to be hit by you, as your insurance is void. Period.
If its your mum then enjoy when you can, as im sure your mum will not want to give you the keys.
PS. The insurance will ask you who the main driver of the car will be, and this will be in black and white on your insurance policy.
i have to agree with the comments above, there really is no point lying to your insurance company, they will always catch you out in the end and even if your a really careful driver its not always the way you drive but the way other people do.
insurance will be very expensive for you mate but you really need to do it right, try putting your mum and another older person on it and see if that bring it down a bit