Here's one way South African highways are better than English highways: on English highways there are no signs to tell you the speed limit. Either they have no speed limit - and despite my eternal optimism and willingness to give it a go in the face of foreign laws, even I recognised this as unlikely - or the English, those notorious domestic colonialists, just Anglocentrically assume that everyone is familiar with their regulations and standards. This is inconvenient when you're trying to drive from Cornwall to London as quickly but as inexpensively as possible."You're going too fast!" said my wife."It's only 120!" I yelled over the juddering car and my pounding heart. She peered at the speedometer. "That's in miles per hour, not kilometres."I didn't reply; I was too busy running a complicated calculus. We were delayed through Devon; if we maintain a swift and constant speed and there's no traffic we'll just reach Heathrow by 2.30pm. Any later and we pay another day's rental and possibly miss the prepaid minicab into London. The financial implications of slowing down are considerable, but the fuel needle is dropping fast. Should I stop for petrol? What if I run dry? But what's the point of not running dry, if it means I arrive late?I'm not ordinarily this tight with cash. Well, I am, but in England I'm worse. Paying in pounds with rand is like being mugged from the moment you wake till you lie down at night and pray they haven't found a way to charge you for your dreams.I did everything I could to cushion the blow - stockpiled miniature wine bottles from the flight; remembered not to put my phone on roaming; made extra sure by leaving my phone at home - but then the rand lurched against the pound again and it was like finding myself in the ring with Mike Tyson when I was expecting Floyd Mayweather.I'd been transported into the future and I was my own grandfather, tutting and shaking my head over the price of things nowadays. I was Tarzan, hauled into civilisation and expected to buy dinner using a loincloth stuffed with peanuts and shiny pebbles.Each time we sat down for lunch and I frowned over the menu my wife kicked me and hissed: "I know what you're doing.""I'm deciding between the pie of the day or the pie of the week," I protested."You're multiplying everything by two and adding a zero," she'd reply. She was right. How could a ploughman's lunch cost R300? What was this gentleman ploughing? Rubies? I solved the problem with elegance and economy."You can't have a pint of ale for lunch," said my wife."I certainly cannot," I agreed. "It will take at least three."Ale for lunch for two weeks was a good idea, because it combined nutrition with recreation and encouraged naps. You can't go broke while you're napping. Before my lunch and after my nap I took long walks through the meadows and along the giddy clifftops, nibbling on handfuls of raisin bran and rashers of bacon I'd scavenged from the complimentary breakfast.The innkeeper had a beagle who sat at the doorway to the dining room, presumably to uncover South Africans trying to make it through the day at the expense of his breakfast buffet, so sometimes I dropped the bacon out the window wrapped in a paper napkin and hustled around outside to retrieve it. Once I had to fight a gypsy for it.On the last day in Cornwall I casually groused about the price of my lunch. "Strange," said the bartender. "People usually come out here and say how cheap the pints are.""Just where do these implausible people come from?" I demanded."From London," she said. " 'Ere, why's he crying?""We go to London tomorrow," said my wife.And so there I was on the A4, trying to eke out a tank of petrol. I freewheeled downhill, I slipstreamed police cars. The "Empty" light came on. It started flashing. We needed the bathroom.We took the off-ramp to Terminal 5 with the car starting to sputter. It was 2.26pm. I sobbed tears of nervous frustration at a red light, I howled like a wookie when I took the wrong turn. With a minute to go I pulled up at the rental place. The engine rattled, wheezed and died. We'd made it."We must refill the tank," said the eastern European assistant."Sure," I conceded."We charge double for this service," he said. "It's very expensive."I couldn't fight any more. I gave him my wallet."Just take it," I said. "Take it all."..