Well I agree that the ad text could do with a slight makeover.
TBH I am a bit shocked that you've had no interest in it, before you re-list it I would try it on Autotrader first, remember only a very small percentage of car buyers have even heard of Pistonheads, most will go to Autotrader. Try a £20 ad for a couple of weeks first.
I sold mine last year for £17.5k straight to a dealer, marginally better spec than yours, but even so, I think £13.5k is just too low. Have you tried any local dealers yet for a cash buy?