How do I get my Cuda card working with AE CS6?

A couple of months back I swapped back to Premiere Pro after a few years on FCP. I soon discovered that it was better to have the Mercury Playback Engine (MPE) working for maximum performance. With the help of a few guys on the Premiere board I was finally able to do that using a GTX660ti card and some tweaks to my Mac's settings.

Note this particular card is not technically supported for the Mac, but using the workaround it is (as far as I can tell) 100% working inside Premiere Pro. I used the method described here: http://nrsotw.blogspot.co.uk/2012/07/enabling-mercury-playback-engine- for.html

So all was well and good until recently when I started to learn AE CS6 and going through my setting I saw that 'Ray-tracing' under Previews in Preferences, has GPU greyed out. Since I have a CUDA card I assume there might be some way of having this set to GPU and unleashing the beast... so to speak.

Incidentally the status blurb underneath the Ray-tracing reads; 'GPU not available - incompatible device or CUDA driver'.

Currently I am using this CUDA driver: http://www.nvidia.com/object/cuda-mac-driver.html

Can anyone give me advice on how to get the GPU aspect of AE working with my GTX660i?

Thanks.