I'd like to make some aftermarket modifications but I can't find a cheap service manual anywhere. Does anyone know where I can get a relatively cheap one for a 2004 MINI Cooper S, R53 design?

 

Haynes and Bentley are the only two service manuals available in printed form. The Haynes is under $30 (much cheaper than Bentley). The Haynes volume is physically much smaller than Bentley, but actually contains about the same amount of info (I have both) because its pages are much more dense (smaller print and photos, and much less empty space than Bentley).

Online, there is this: http://tis.spaghetticoder.org/

 

Thanks for the online link! Looks like the link will work for what I need