The 2006 Adventure will not support the AI upgrade. The mold was changed in the 07 models to include embedded fittings to receive the crossbars.
An easy way to tell is to see if the boat has 4 pair of screws on the rails where the crossbar mounts would be. Here is a pic of the right front pair (in green highlight):
The Adventure makes a great kayak in its own right though and is fun and challenging to sail with the small sail. Of course, it's not an AI.
If you're inspecting the boat, look closely for any cracking in the cam columns.
There is a way to repair this -- use the search feature to learn more.