Season 36

 Season 18 used a more 3D looking version of the oval category strips, and still had the "rolling wheel" effect.  Just that the wheel rolled from right to left, and the category stripped "popped out".  Season 19's category strips completely changed, and had a left-to-right ripple effect.  They changed again in Season 20, new font, blue background with green border, had a "fall into place" effect.  Season 21 retained the font from Season 20, but the background was changed to a lighter blue to match the set (it was the first season to use the current set), a different "fall into place" effect.  Then in Season 22, the category striped were changed to a darker shade of blue, and had a "searchlights effect", but retained the font; however, the category strips for the bonus round were the same from Season 21. And finally in Season 23, the font was changed, "searchlights effect" retained from Season 22, and the bonus round category strips were also changed.

Tape dates August 9 and 10th

The current set indeed dates back to 2003, but it's undergone several revamps, especially since the show began broadcasting in HD.

During the first season with the current set (Season 21), the bonus wheel from the previous set was carried over but the red lettering was changed to blue.  First generic backdrop debuted around mid-March 2004 and remained there until the end of Season 27.  Then in Season 22, the bonus wheel was changed to plexiglass and LEDs to match the set.  Season 24, the area of the set was widened for the 16:9 aspect ratio to accomodate the transition to HD, and the wedges on the wheel were given more vivid hues of their respective colors.  Season 25, we saw the puzzle board revamped with flat-screen monitors, and the contestant scoreboards were changed to plasma displays and were no longer touching one another.  The bonus wheel was slightly changed in Season 26 to read "SPIN & WIN AMERICA'S GAME".  During Season 27, the contestant railing was modified to include more LED strips; and two months into Season 28, the current generic backdrop was introduced.  Season 30, the scoreboards were widened and touch one another for the first time since Season 24, and a fourth monitor was added where Pat stands and displays the WoF logo throughout the game.  Finally in Season 31, the bonus wheel was recolored, and the lettering was changed to yellow.