This is a difficult question to answer, but having done such mileage in only six years suggests it's done lots of high speed motorway trips. This is when a car's mechanical components are under the least stress - the engine is warm and turning over at a constant low-ish rpm, the gearbox isn't being stressed and the suspension isn't working too hard. If that's the case, we'd say your Superb should have plenty of life left in it and could well see 200,000 miles without any issue. We can't make any guarantees though - it might be worth looking into an aftermarket warranty.