Pull away from standstill, and Aygo's engine suffers a prolonged flat spot before it begins to pull from around 4000rpm. As a result it has to be worked hard to make decent progress, and you'll often need to change down a gear - especially on hills - to maintain a steady rate of acceleration.
Pushing the engine also exposes one of the Aygo's weakest areas: its refinement.
There's a considerable amount of engine noise in the cabin, and as the revs rise so does the vibration felt through the steering wheel and pedals. Furthermore, there's noticeable transmission whine as you come off the throttle, and the thrum of the exhaust beneath the rear seats is a constant nuisance.