Here are some useful Web links I've found.

A really good motoring based web forum, plus online magazine content - mainly the forums I tend to use though.

Kenlowe make some really useful bits for cars - their electric cooling fans are well known, but they also make some really neat engine pre-heaters, which I've used before - they use an electric heater to pre-warm the engine coolant so the engine starts from normal operating temperature, and you get warm air straight out of the vents - great for de-misting! It also really drops the fuel consumption of your car if you're doing a lot of short journeys.