i havn't tried this yet, but i think it might work and could potentially be pretty accurate. get a set of virgin rims with no cracks/scratches or dents and go and mount them onto your car. you don't want tires to be mounted because tires stick out further than the rim and can be slightly inconsistant with its give. get a piece of paper and draw a centre line where you can centre your car onto lengthwise. now get a ruler, preferably metal as they seem to be the most consistant and dont seem to ever get dents, and place it horizontally against which ever rim youre testing the toe on(don't worry, ill supply a picture to better explain my madness). with the ruler, you get a more accurate measure of the toe because you can extend the tires line even further than the rim. with some math you can find out the toe on each wheel and so you can have better symmetricity from one side to the other instead of the checking overall toe from one tire to the other. does it work? i dunno, maybe, i havn't tried it and i havn't taken math in along time, but i THINK it works. as for the math, itd probably be something like take the number from the outside of the axle to the centreline, and compare it to the number at lets say...20cm out. now take the difference between the 2 numbers, and you have the height of a triangle, the 20cm is the length of the triangle, and the hypothenus you can solve with asquared + bsquared = csquared, and with all those numbers you can solve for the angle. either that or just use a marker/pen/pencil, mark all the points, and take a compass and check the angle. whichever floats your boat.