I have just bought a 1999 Volvo AWD estate in excellent condition with just 71000 miles on the clock but there is an occasional loud popping noise that seems to come from under the dash near the glove box, the first time I heard it I thought a stone had bounced off the windscreen, I contacted the former owner and he said he had heard it to but forgot to mention it to the garage at the last service. Has anyone had the same experiance or have any idea what could be causing it? thank you all.