After I lowered my celica, I had about 3-4inches ground clearance under the front spoiler, and although the bottom of the car had much more clearance than that, I still cant drive over certain speed bumps without doing some damage.
The trick is...drive into every driveway sideways and slowly. My suspension is so stiff that the right rear wheel would be several inches off the ground...its pretty cool

Although there are still some driveways I cant pull into at all.
So the stock elise should be fine...just drive slow into driveways and over speed bumps.