Is there away of loop recording so you can hear what you have just recorded once the loop restarts and layer it? Or even loop record so the audio/midi plays back once the loop restarts (good for live jams in the studio)

record in sound on sound mode.
 
there are 3 recording modes:
- Comping
- Overwrite
- Sound on sound

I'm sure I've tried sound on sound mode but will try it again to make sure. Thanks

You can with midi, not with audio, unless it's been changed recently. 

+1 on Chucks answer.  It should definitely work with audio.

As the OP has discovered, SONAR doesn't make previous takes audible while loop-recording audio in Sound on Sound mode. They only become audible after the transport is stopped and restarted. Here's a workaround I re-posted in a recent thread:
 
Original post from 6 years ago:
 
http://forum.cakewalk.com/FindPost/2083051
 
To summarize:
- Insert a delay capable of very long delay intervals in the audio track, and set the delay equal to the loop length. 
- Set the Feedback to 100% with a 50/50 Wet/Dry mix. 
- Enable new layers (now lanes) on overlap, and record away.
- Each new loop will be repeated endlessly by the delay, but each recorded layer will contain only what you played on that pass.
- Use a keybinding to stop the audio engine after stopping the transport to kill the delay feedback. 

im doing it here in this video in sonar x2. (using midi) and you can hear the previous takes as it loops.
Start watching at 4:12
 

Yeah, Chuck, it works with MIDI but not with audio.

Th3 has a looper stomp box, but you can get clicks around the loop ends.

brundlefly
Yeah, Chuck, it works with MIDI but not with audio.

my bad, didn't read your first post good enough.