There are a couple of gaps (most noticeably the drive up to Gullfoss, I only got the route back, which was slightly different) - but here's a google earth track of my Iceland trip - though I doubt that anyone is interested except me! If you have google earth, save the kml file and then double click on it (google earth should launch - if it doesn't try dragging the kml file onto the google earth icon).
If you don't have google earth, then you'll need to install it to use the file. It's free.
Reykjavík is the busiest part of the map, unsurprisingly - though there are lots of small gaps in the track due to signal loss.