My girlfriend is understandably complaining about the lack of performance she is getting from her 54 plate 1.4 Zetec Fiesta. Especially since I got my 4x4 Saff last week

. We've looked at chopping it in for an older S2 RST, but she does do a fair few miles everyday and needs the car to get to and from work, so the older car would probably be the wrong move. What minor mods can we make to increase the performance?? I'm not looking to spend thousands or change the engine etc. Figures state it is 80PS, so even to increase this by 10 or 20 bhp would probably make a big difference.
Let me know your ideas
CheeRS
Paul