How to replace multiple materials at once

[andreicoroi]

Hi

I have a very detailed model, a car, with thousands of meshes, in total there are around 100-150 materials and I cannot find a way to replace multiple materials at once. 
Example: 50 meshes with 10 different types of plastic. I would like to replace all those 10 materials with one single generic plastic material, preferably in a quick way.

I come from Cinema 4D, there you would just select all the 10 materials with shift and right click, replace with.

[Mr.Mxyzptlk]

Select the all of the objects you want the single material on and apply the new material to that selection?