Check out this map I made using my Garmin GPSmaps 96:
This is just a screenshot so it you can't see much detail but if you click HERE to download the file and see in Google Earth. You can zoom in a on the map and see exactly what I flew and even see where I parked at the airport.
Here is how I did it. Garmin came out with this program called BaseCamp. You can just upload the route you flew, drove, hiked, whatever. There was lots flights on my GPS just select the one you want, this one is a flight I took a few weeks ago. Then there is a menu at the top where you can view your selected route in Google Earth. Then to get it from Google Earth to maps you export it to a .kml file. and upload to a site like Google sites and you put the link of the file in Google maps and it will show up as shown above.
This is the only way I could figure out how you do it. If anyone know an easier way let me know.