Here is a list of parts that are available through TM tech support. These parts are available for free provided your Cougar is still under the two years warranty. All you need to do is to subscribe to the Thrustmaster technical support website and file your part request through there: http://ts.thrustmaster.com
If your Cougar is not under warranty anymore, then the only way to get spare parts will be by purchasing the spares parts kits. These kits unfortunately are not available yet, but as all Cougars are still under warranty, this shouldn't be an issue (at least not yet)

Please note that the part reference number shown below is for information purposes only. TM/Guillemot uses the same list at the moment but they can change their system without us being notified. In all cases, use the description of the part and not the number only.

Note also that soldering may be required to install warranty parts into the Cougar.

A slight note of warning here. It's not because that list is now available that you can now overload Guillemot tech support with part requests. Do it honestly and request only the part that is broken. So far, Guillemot/TM don't ask question about the part you're requesting but I already heard some remarks about some abusive requests. So if you, like me, want the system to continue in the long run, you know what you have to do ;)