All great advice. If I may just add my own philosophy on practice it would be this, especially if you have time issues, but in general this is my own approach.
Have a specific task in mind. When you sit with instrument in hand or lap, have a goal.
During the day give some thought as to exactly what you wish to accomplish. It may be a particular section of a song that is giving you problems, or perhaps you may want to work on a scale (pick one and stay on that one) or work on turnarounds in different keys.....anything you choose.
When the time comes to sit down and play your attention will be focused on one task. As brilind said, "zen like". I agree totally.
With a specific goal in mind your 5 minutes will be spent more efficiently than 30 minutes of random noodleing, as much fun as that is.
The bottom line; playing anything for 5 minutes is better than not playing at all.
Just my 2 pennies.....thanks.
John
Oh! and don't get rid of your Harley!!!!!