This is the known issue that you may or may not see on all ST170 car, which are usually fixed under standard Ford warranty.
Turn down the brightness a little bit and it will stop the "flickering effect".
When you reach 4,000rpm or more, the pedal vibrates. Have the cable replaced - TSB number is 24/2004 - "Accelerator pedal vibration - (cable mod), 30/03/04, Buiid codes 2Y>3P". Using FINIS codes 4573474 for the cable and 6793327 for the clips
When you lift completly off the pedal & reapply, it will be a bit hard to push down and when you do, it "clicks" when you have pushed the pedal down - possible related to above or a dodgy hinges.
Update: Got the Accelerator cable replaced, this is now sorted. So it could be this.
Update 2 Also check the Throttle Body - the build up of dirt around insides of the throttle body will cause the butteryfly to stick.
Lambda Sensors may fail, causing the Engine Management light to come up and stay lit. Take it to the Ford garage as soon as possible. If it starts to flash, take it to the Ford garage ASAP and don't drive too hard.
The headlght may be steamed up, starting from the bottom and upward. This is a known issue on 02, 52, 03 and 53 reg plate, but seems to be fixed on future models. Someone suggested using Silica Gel bag inside the headlights (not the silver area, just before it) which seems to have cured the problem. But it would mean taking it apart which is not advisable unless you know how to do this task.
The rattle noise may be heard when you are around the 2,000rpm mark. This usually means the bracket of the heat shield for the catalytic converters might have come loose/broken and this needs to be fixed. Some garages may tell you that you need the whole new CAT exhaust, but do not accept it. This can be fixed for about £30 and the FINIS code is 4708066.
When the IMRC cable or the clip break, you will hear a loud clicking noise that's coming from the dashboard. It's actually in the engine bay, toward the firewall, you should see the silver box in the back. You should see the cable going into it. That would be the Engine Air Shut Off Control (IMRC actuator) - FINIS 4447983. And also the Manifold Kit - FINIS 1367457 - if required. That fixed the problem I had.
I only had this happened to me once and was able to repro it. What happened was when you switch the sidelight on and then go to main beam with very little of a delay between both of them and the green backlight doesn't come up. Turning it off and then on will get the green backlight to come up.
The rattle noise may be heard in the engine bay when the engine is running and it would be more likely to be the manifold heatshield that is coming loose. Have a closer look at the area where the nuts are - you may find it has rusted away, where the heatshield come off from it easily. A replacement heatshield will fix this.
The rattle noise may be heard from under the car when the engine is running and it would be more likely to be the CAT heatshield that is coming loose or broken. See my HOWTO to fix it without spending too much money.