You cannot really compare motorsport with production cars, can you? Most of the parts for racing cars have to fulfill much thougher quality standards or are replaced every 1000 km or so. (Remember that it was a novelty one year ago when an F1 engine had to last at least two races = 1000KM?)
There's no doubt that many technical inventions first seen on race cars have improved the power of efficiency of road cars, but reliability and durability only can be tested in real life.
And I fear if Peugeot, Citroen and Renault don't do something about their quality issues (there's a huge survey done by the German automobile club ADAC in which French cars turn to come last as well, so that's not only a UK issue) they might take not only a temporarily damage in reputation and popularity.