DON'T GET A VOLVO. I think they're more yawn-inducing than the A-class.
I learnt to drive in a little Toyota Yaris. Not sure if you'd get the newest shape for £3,500 but my aunty has a 2004 Yaris (the old model), she usually buys a brand new car every 2 years or so but has refused since she's had the Yaris.
The one I used was great to drive, lovely little car.