Anyone know how to script this?
after Recording a take, as soon as Space-bar is pressed this series of actions will happen:
On stop rewind to Now Marker> Solo any Rec armed tracks> Auto Play
 

Can't be done with CAL. CAL is mostly for manipulating MIDI data.

aww, man.
 

Rewind to Now is done by Sonar itself. AZ Controller can do switching. At the moment, till some degree, there is no loops, so rec -> solo is feasible to do for WAI set of tracks only (can be 8 .. ~32). It is possible to write specialized function which can work with any number of tracks, if you are seriously going to use the result.

I were you I would set up a group.
Group all the rec tracks and when you stop recording, hit one solo button and all your rec tracks (that group) will be solo'd.
that's the best I got.

I decide that such function can be useful in general. Example preset is there: http://www.azslow.com/index.php/topic,298.0.html