The great thing about birding is now I never get bored on those long journeys on the motorway. Every time I make a list of any birds of prey I see, and compare the results with my previous long journeys. Here is my list after crossing the whole of England from Manchester to the South-East: (It was raining quite hard most of the way, and I dozed off at one point, but my familly kept up the count for me)
10+ Buzzards
1 Kestrel
c10 Red Kites

I've had better days, I admit. In France, thought the buzzards almost always win (in the 20s), they battle for the top with the Kestrels, and I've had counts of both kite sp. as well, harriers, ect...
How many birds of prey can you see? Obviously, safety first, so if you're driving, keep an eye on the road at all times.