I've also driven from Bristol airport to Drogheda (via Fishguard and Rosslare) in December 1999, on a very cold weekend, in a 1968 Morris Oxford, with no heater, and no matter how hard I pressed the accelerator, the car refused to exceed 50 m.p.h. Overnighting in both Bristol and Rosslare, I also discovered the key wouldn't unlock the driver's door, so had to quickly adapt a teaspoon to break in to my own car!!!!