When you're trying to keep an ancient car going on a tight budget, you get to visit dealers so far from polished main-franchise service bays they might as well be in another industry altogether.    

I retain a particular fondness for Irvine, an elderly gentleman who ran a wonderfully named outfit called Mercy Spares in the railway arches at Deptford. He presided over a cavernous series of filthy catacombs stuffed full of miscellaneous oily components, seats spewing stuffing and springs, rusted body panels and the odd feral cat. You could only enter sideways, nervously looking above for fear of an engine or something similarly heavy toppling off one of the precarious roof-high heaps.

'How on earth can you find anything?' I asked. Irvine grinned, and tapped his forehead: 'I have it all on computer!' He dived into a mass of seemingly unidentifiable bent pieces of old metal, there was a scurry of rat tails, and out he came with a pair of perfectly usable rear suspension arms.

Railway arches have long hosted garages that make the fictional Arches - the garage in EastEnders - look like a slick, upmarket professional operation. Yet they're not all botch-it merchants, cut 'n' shut bodyshops or glass tinters and purveyors of shiny alloys and cheap bodykits: some of the most respected classic car restorers and independent specialists occupy the most unprepossessing premises with trains thundering ahead.

But how much longer can they stay there? The boom in property prices has seen so many small garages across the country forced out of city mews, small industrial developments and any spaces ripe for redevelopment. The last few years have also brought new bars, cafes and boutique shops in most areas undergoing gentrification. When leases come up for renewal, rents are raised and the old businesses driven away.

Along with additional legal requirements, health and safety rules and EU impositions such as the end-of-life vehicle disposal reforms, this is spelling the end for many of the old-school breakers and parts suppliers. And in turn it's making it ever more difficult to keep an older car on the road at a viable price.