QUICK!
Where can I get a 64-bit kext for my old ATI X1600? I want to install this on my 2006 MacBook Pro!!!
Didn't the 2006 MacBook Pros only have 32-Bit Core Duo CPUs? I know that later 2006 iMac models were upgraded to 64-Bit Core 2 Duo processors, but I don't recall if there were also re-configured MacBook Pros in that year - it's too long ago. If you only have a machine with a 32-Bit Core Duo processor, you can't install ML on that machine anyway.
If I were you, I'd probably put Windows 8 or a Linux flavor on that machine instead of wasting my time on an unreliable Mountain Lion hack.