Mike,
I used to own a house that pumped water between the slab and the footing wall if it rained for a week straight.
We had a company come out and install a french drain under the slab along the footing wall on the two sides that had the issue, they then ran the outlet under the footing and into a dry well in the front yard.
The next major rain event had water wicking along the seam between the new and the existing concrete.
The company came back, painted an epoxy sealer along the seams with the parting statement that the dry sump wasn't perking the water sufficiently, and that the floor will probably continue to wick unless I either daylight the drain or stub it into the storm drain in front of my house.
I ended up stubbing into the cities storm drain under cover of darkness
No more problems.
Seems like where you garage/shop is located its fairly flat and hopefully you won't be faced with the issue we had.
You might try calling a commercial concrete sealing company and ask what brand product they use.