This one needs a little explaining to me.

This fits on the back side of the clutch pedal, so to me, it seems it won't allow the pedal to be pushed all the way in? Does it not need to go all the way in, and if not, then why bother with an extension and instead just not push it all the way?

I don't doubt that if this place makes it, it's fine to use, I just don't get the concept myself.

@triviawayne I read the link and studied the picture.  You take the rubber off. This attaches so that about 1/2 inch is below, and now the new top of the clutch pedal is raised almost 2". The original rubber pad goes back onto the top of the adapter. I think the pedal doesn't actually contact the floor, so that extra 1/2" must barely clear bottoming out.

@livetodrive I get it now.  I just couldn't see it right the first time.  Thank you.

@triviawayne I would have thought the same thing too, at first glance. But since you said it seemed odd, I was intrigued. 

With the extension fitted, the clutch pedal pad is 1.5 inches closer to the driver than stock.  It allows the driver to push the seat back farther without stretching his or her leg to fully depress the clutch pedal.  Nothing contacts the floor.

Goodwin sells these for all generations of Miata, and many owners find them helpful.  It's difficult to describe until you feel it for yourself.  It does make a substantial difference.

@mike-c I remember my mother having pedal extensions on cars in the 70s, even for an automatic car.

I think it can be useful in the Miata, but then I'm thinking I would need a dead pedal extension 😛

@triviawayne   Yes, I remember them, too.

This is similar to the pedal extensions we remember from our childhoods, except it's made specifically to fit the ND clutch pedal (which is plastic, BTW), and it fits precisely.  Once it's tightened in place it does not move at all, and it reuses the original rubber pedal pad.

Some ND drivers are uncomfortable with the closeness of their knees to the dashboard, especially in case of a crash, and this pedal extension allows them to gain a bit more clearance.

SOLD!