Matey.
I got my tonneau through Holdcroft and it came out at £77 with the discount.
BTW You definately cannot adjust the headlights from inside the car.
I'm not sure about the SVA guys doing it, but if you have any garage change it and issue a statement confirming the mileage prior to the replacement, so long as any potential puchaser is made aware of this change, there's no problem.