I'm pretty sure almost any modern (2000+? maybe earlier than that) economy car uses DFCO, it's just something that most people didn't know about until the recent hypermiling trend.

You can tell really quickly with a ScanGauge or other OBD diagnostic tool. Fuel flow will drop to zero (among other things).

There are some sneaky ways you can check to see if you have it, though. Try accelerating up to a cruising speed in 2nd or 3rd gear (just because being in a lower gear will give you higher revs and more uninterrupted coast-down time) and then lift off the gas leaving the car in gear. Take note of the sound of the engine and the feel of the deceleration. Now, do the same thing again, but shortly after you begin your coast, turn off the ignition for a few seconds. If you have DFCO, no fuel was being burned, so nothing should change when you turn off the ignition.

Another way you might be able to tell is to hold the lowest gear your transmission allows you to select. Accelerate to maybe 20 mph, just enough to get the revs up. With the trans in low gear, it won't downshift, so you should feel smooth deceleration when you lift off the gas. With DFCO, you'll decelerate with no fuel (essentially, the engine shuts off) until the RPM gets to the point that it needs to sustain itself (somewhere around 1000-1200 rpm), then it will add fuel and the engine will "restart" itself to maintain its idle. You can feel a gentle surge when that happens.

If you find that you have DFCO, it's probably better to make use of that than shifting into neutral. Remember, shifting to neutral uses "some" fuel, DFCO uses "none". If you go down a looong hill (the kind we don't really have in FL), there may be benefit to using neutral to get a longer coast, but for our short coasts, especially "stoplight coasts" where you need to decelerate, anyway... you're better to use DFCO.

I'll warn you, though... just like the pursuit of speed, the pursuit of better gas mileage can become an obsession!