On the East Side Gallery - a 1.6km-long chunk of Berlin Wall preserved as an alfresco art exhibition - is one image that sums up the city's tumultuous history: a painting of an East German Trabant car smashing through the concrete barrier. This, of course, is pure fantasy. With bodywork made chiefly from compressed Russian cotton held together with resin, the 'Trabi' would struggle to survive a head-on collision with a cardboard box, let alone a wall.
Since German reunification in 1991, BMWs and Mercedes-Benzes have largely chased the once ubiquitous Trabi from Berlin's wide boulevards onto the scrap heap - or more ignominiously, into the farmyard, where they make good homes for chickens. But 15 years after the last one spluttered off the production line, some Trabis remain in action. A small fleet has been assembled in the German capital for a tourist venture that lets visitors roam the city behind the wheel of a socialist icon.
On a Berlin side street I meet Erich, a cheerful, powder-blue 1989 Trabant P-601, and Benedikt, an equally cheerful and - thanks to face-freezing temperatures - equally blue Trabi Safari guide. After a lesson on how to negotiate the wobbly four-speed gear lever mounted on the steering column, a turn of the ignition kicks Erich straight into action and we lurch towards the city traffic ahead of a smelly plume of exhaust fumes.
We're an immediate head turner, not least because of the distinctive two-stroke engine rattling beneath the Trabi's bonnet. With Benedikt giving directions from the back seat, a style of driving that must have been all too familiar in the cloak-and-dagger days of East Germany's notorious Stasi secret police, we head down east Berlin's Karl-Marx-Allee, where Erich looks instantly at home among the grim 1960s housing blocks.
After pausing at a set of traffic lights I put the engine through its paces, roaring from zero to 90km/h in a leisurely 25 seconds. 'The Trabi has a top speed of 110km/h,' deadpans Benedikt over my shoulder. 'But only when the wind is blowing from behind. On a steep hill.'
I try to imagine Erich careening down The Peak into Central. It's an amusing idea, but then there is the problem of deceleration. The Trabi's 26-horsepower engine isn't strong enough to assist braking, so shoving it into a low gear merely cranks the revs up to a deafening scream. Its non-power-assisted drum brakes perform surprisingly well on the flat. This is mainly because they have only the car's lightweight chassis to contend with, which is fine unless you're giving a lift to a former East German Olympic shot-putter.
How the Trabi would cope with the Hong Kong summer is another matter. Sweltering July temperatures would probably test its resin to melting point and, unlike the swanky motors that ply Gloucester Road, it has no air-conditioning to stave off the humidity.
Plenty of other things are missing. There is no automatic switching on the indicators and, more vexingly, no fuel gauge - drivers must probe the 25-litre tank with a dipstick to find out how much remains of the hand-blended mixture of petrol and oil that fuels the car.
In the tiny compartment containing the 0.6 litre engine there is no room for valves, camshaft, radiator, timing belt, oil pump, water pump or anything else made of steel. When the vehicle was created in the 50s, this solved a basic problem: at the end of the second world war, Russia expatriated most of East Germany's steel presses. The forced hybrid of motorcycle and bubble car was seen as a temporary compromise, but since the shape changed little after that, it seems the Trabant's design team was given the rest of the Cold War off.
With little else on offer, East German citizens snapped up three million Trabis in the next three decades. Most customers faced a 10-year waiting list, a state of affairs that reflected the country's ailing economy and inspired the following joke on an East German television show: Trabant factory: 'Hello Herr Schmidt, I'm calling to tell you your Trabant will be ready in 10 years, on October 14, 1998.'
Happy customer: 'Great! Can you tell me whether it will be delivered in the morning or the afternoon?'
Trabant factory: 'Are you mad? I said it won't be ready for another 10 years.'
Happy customer: 'Yes, I know. It's just that I've got the plumber coming that morning.'
The Trabi has rightfully earned its place in the pantheon of risible runabouts, alongside such greats as Russia's tank-like Lada, the motorised toad that was Britain's Austin Allegro and the three-wheeled lunacy of the Reliant Robin, another triumph of British engineering. But its low-quality credentials are highlighted by another classic car joke, the one about Serbia's horrible Yugo having heated rear windows to keep hands warm when pushing. The Trabant, it seems, doesn't even have the window heaters.
Not surprisingly, according to Benedikt, Trabis can be purchased in Germany for a mere $5,600. Spare parts are available for the few on the market, but their declining supply means ailing vehicles are being all too quickly plundered for their innards. Outside Germany, the Trabant's rising cult status and increasing rarity mean prices are climbing. One Canadian website has starting prices of almost $40,000. Abroad, there are usually a few minor costs to be incurred in bringing the Trabi up to legal road-safety requirements - new engine, new wheels, new brakes, new lights, new chassis, that sort of thing.
As we pull to a halt outside another Soviet relic, Berlin's soon-to-be-demolished People's Palace, I'm reluctant to finish my Trabant experience. I hug the steering wheel and picture what could be: Erich and me, chugging happily along life's highway at speeds of less than 110km/h, a mobile monument to Cold War cool.
Benedikt reads my mind. 'You like the Trabi? Good. Now give me back the keys,' he says.
There is a brief stand-off, then I realise the holiday romance is over. I picture the reality of Erich being overtaken by cyclists, wheezing to a halt when his fuel runs out, or lying mangled on the roadside after a run-in with a squirrel. I give Benedikt the keys.