Thank you all for the greasy tip!
On the tyre front, thank you for the link Steve - I didn't know tyres were dated.
On investigation, the reason for the boy racer squeal becomes apparent (particularly during the Bromyard Speed Festival):
Front Offside - Continental Contact, 2814
Front Nearside - Continental Contact, 2814
Rear Offside - Firestone F560, 4900
Rear Nearside - Firestone F560, 2604
Spare - Firestone F560, 2604
The tyre making all the noise has been on the car since new. How embarrasing. Time to spend money, and improve roadholding and safety...but only three tyres for now. That leaves me with some cash towards a new radiator.
