I always switch everything off going downhill.
And if it is raining, switch off the wipers when you go under a bridge

Actually, coasting or freewheeling down a hill is a pretty good idea, but you need to be careful if you are loaded!. Years ago when working at a Saab garage i had the opportunity to deliver a customers 96 V4, they came as standard with a freewheel (which you could disengage if you wanted). When driving along, with it engaged, you simply take your foot off the throttle pedal and hey presto, you are freewheeling. With some practice it could make quite a big difference to the mpg
