other than the cupra, if you get any mk4 TDi you can great gain for relatvily little money. If you look for Sportriders ride in the readers ride section you'll see what i mean. He started life with a 1.9TDI 100bhp engine, a few mods later, 160bhp 250ft/lb torque, its now quicker than a stock mk4 cupra tdi. I no it refuring to the dark side, but you will certainly notice the overtaking power of the tdi, compared to a petrol (i used to own a 64bhp 1.2 and a 100bhp 1.4 so i can vouch for that)