Having only 6 AA batteries for the 4 motors wasn’t enough, and even with my super friction-reducing sellotape, the car struggled to turn on the spot, with 1 or 2 engines normally stalling. A maximum of 9v was being provided for the 4 6v motors (connected in parallel), resulting in around 2 volts per motor (max) at a quick guess. I grabbed an 8 battery holder from Maplin, hooked this up and the car is much happier now – can turn on the spot well, and goes a bit faster too.
As well as my emergency lighting system (ELS), I made a tiny script to simulate hazard warning lights, for when the car is just pulled over at the side of a room. The interface to control the vehicle is very simple – yet functional! When time allows, I will break out the CSS and get it looking a bit fancier.