Nolan Space is defined by its two dimensions of 1) economic liberty vs. legislated equality, and 2) personal liberty vs. legislated morality. Nolan Space is not defined by the WSPQ. Any Nolan-Space quiz that broadly surveys economic and personal freedoms should plot the Greens farther out on the left-right equater than the D's and R's are, and thus farther away from the LP than them.
I've got a back-burner project going to compare my own version of the Quiz with seven leading alternatives (including Carl's), and I'm already confident that mine plots the most interesting parties/ideologies (LP, D, R, G, CP, Nazi, Communist) more intelligently than any of the others. Mine is at http://marketliberal.org/Ruler.pdf.
My other competitor to the WSPQ is one that packs twice as many questions into half the space, for use on the back on my campaign business card: http://marketliberal.org/Card.pdf. It's not quite as accurate as my full quiz for all the above parites/ideologies, but it seems like a space-saving way to combine a quiz with a miniature legislative program.