So did I. I just bought an Audi A6 from big motoring world just month ago and noticed some mechanical faults outright after purchase. Despite several email correspondence and fone conversation they have not practically done anything to repair. They also refused Audi diagnostic centre report of issues. So Im definitely going to refuse and return this back and claim refund ASAP under right to reject under the Consumer Rights Act if the car is unfit for purpose, of unsatisfactory quality or not as described. You can ask for a repair or replacement, but you're not obliged to accept one and can insist on a full refund, which the dealer will be legally obliged to give.