Question
I would like to widen my existing driveway onto my lawn to accomodate overflow parking.  Essentially about a 3ft wide by 6ft long section to support half a car (the other half would be on the existing driveway).  

I was wondering how to accomplish this section with some combination of paving stones that had hollow centres filled with soil prehaps so that I can still grow grass within this section and have it appear as a transition plot between the regular lawn and asphalt driveway.   

Currently, the cars that have parked partly on the lawn at times have chewed it up and gets really muddy when it rains.

Thanks for any advice you may have!

Mike in Ottawa,Canada

Answer
3 x 6 isn't a HUGE problem.  There are a number of products out there, and basically 3 ways to address the issue.  

You can add reinforcement on the surface in the form of a plastic grid, rolled out like a netting, used for overflow parking for special events where they need parking on existing lawns - looks like orange "snow fence", except it is green. (http://freespace.virgin.net/hy.tex/ht_geo_tr.html)

Or by adding a plastic reinforcment matt with PCV "waffles", rings, or grid & buried under the turf, like old-fashioned chainmail and great for fire lanes - it will carry enourmous loads!
(http://www.thegridsystem.com/)

And, finally, the concrete turf-block you mentioned.
(http://www.mcpavers.com/turfblock.htm)

I hesitate to suggest specific manufacturers or suppliers, as price is sensitive to region & shipping costs, and I don't know what may be available in Ottawa...I noticed you gave me Imperial units instead of metric, too!!

In reality, for 18 square feet, the block filled with gravel & topsoil will be your cheepest solution, but will probably look the worst.  Next up, would be the PVC grid or rings, buried underneath.  Then the roll-over matt as a last option.

If you are going to the hastle of digging up the dirt and putting an open-grid block down, anyway, why not just extend the driveway width with solid pavers (with appropriate edge retraints)?  

The amount of rainwater that may soak into 18 sf is minimal...

OR if eco-friendly issues are very important to you, you can "repave" the whole thing in lawn using the PVC grid for the entire driveway.  It would work best if you don't leave parked cars on it (as oil & shade would kill the grass over time).  

And of course you'd need a large budget, depending on the length of driveway!  But hey, its easy for me to spend YOUR money!  

Good luck -
~Marc