I built my workbench over 30 years ago and put the deck height at 42" just to make work and tools a bit easier to get to.  A few years ago I gave up some of the length to make room for a shelving unit.  Of course this also reduced available space for tool storage, resulting in stuff stored in different spots around the garage.  Further complicating things is that I keep three cars stored in a slightly oversized 2-car garage so floor space is already at a premium.  I recently spotted a mobile workbench at Home Depot and took note of the dimensions.  Checking under my bench I realized I fortuitously had the EXACT right sized opening for the unit.  All I had to do was clear out and remove a shelf under the deck.  The install took place yesterday, it looks like a custom install, and lots of tools now have a new and organized home! 

Brilliant!