The Smart Roadster has a non-identical twin in the shape of the Audi A2. They were innovative and fascinating cars at launch, very light and rather expensive but intriguing nonetheless. Moreover, both are becoming increasingly relevant in an efficiency-obsessed market with each year since their production runs ceased. Neither was properly replaced either; the A1 may be another small Audi, but the originality that made the A2 so appealing has been methodically eradicated. Launched a decade ago, the Smart Roadster was the downsized sports car we\'re crying out for today. A dinky three-cylinder turbocharged engine, an 800kg kerbweight, rear-wheel drive and c. £15K; who wouldn\'t want economical and cheap fun? But the Smart struggled in a roadster world dominated by MX-5s and MR2s, especially when running a car was a much cheaper expense. As a used proposition in 2013 though, 55mpg from a £3K mid-engined sports car sounds rather alluring, doesn\'t it? With just 81hp though, the Smart would struggle against the Mazda and Toyota on track or quicker roads. So, for some parity, we\'ve found a lightly tweaked Smart which should address the performance deficit and be a whole lot more fun besides. So, a new Janspeed exhaust, Brabus turbo, ECU remap and air filter see this little Smart producing \'over 110hp\' and 141lb ft. Power-to-weight will therefore be around 140hp per tonne, about 10hp down on a GT86. An upgrade to four-piston brake calipers and some new Avon tyres should help you stop as well. However, before you go haring off to Surrey with the cash and planning your track day schedule on the train, a couple of warning notices for Smart Roadsters. They can leak, playing havoc with the SAM unit, the primary job of which is to control the electrics. Sporadic and random operation of equipment like the lights, wipers and radio is the tell-tale sign of water ingress in the SAM and also the indicator of trouble. SAMs can\'t be refurbished, they must be replaced, which includes programming at an M-B dealer; budget around £900. Seals can be treated, but any car can be affected. The vendor here doesn\'t mention any issues. You have been warned... Clutches also need replacing at 60,000 miles, costing around £500. This Roadster is at exactly 60K, so there\'s a vital piece of maintenance to check for. The \'box itself will feel slow with experience of contemporary dual-clutch and automatic units, but it isn\'t the deal-breaker it\'s made out to be. And of course, lighter, smaller cars use lighter, smaller components that need replacing less frequently at lower cost. Brakes and suspension parts just aren\'t put under the stress they would be on something larger, which should be considered for any track frivolities. If the water ingress-related issues can be avoided, this Smart Roadster promises to be about as hilarious as 50mpg can get. Still not convinced? Fine, nice MR2 here then! Source: Pistonheads