Being a foreign word for all non-Germanic, we should not feel forced to pronounce it correctly, in fact we are not expected to do so. In the Americas, it is pronounced "Roll-a". My guess is that in German it would be pronounced "Roll-ee", as they are Franke & Heidecke Fabrik Photographischer Prazisionsapparate.
BTW, the name "Rollei" has an interesting history:
Paul Franke and Reinhold Heidecke manufactured a stereo camera called "Heidoscop". When, in 1928, their first medium format camera which used roll film was presented, they changed "Heidoscop" to "Rolleidoscop" - beeing a abbreviation of "Roll-Heidoscop".
I don't know on which occasion they got rid of the "doscop" and the shorter "Rollei" was born, but it was probably for the sake of marketing purposes.
Peter, from your .wav file, it sounds like Roll-I, which would also make sense from the transition from 'Heidoscop' to 'Rolleidoscop''; in the sense that I would pronounce the former as Hi-doh-scop. There is some extra curl on the "r" in your .wav file, which I probably won't get in spite of my Germanic ancestry - too many generations ago.
I've always pronounced it "roll-E-flex" or "roll-E-cord." What throws me (nearly always) is the arrangement of the "ei" which unless proceeded by a "C" in English is usually arranged "ie." My fingers keep typing in english and I have to backspace nearly everytime...