I've rented a CMM arm in order to plot the 3D coordinates (with mediocre accuracy) of all of the suspension points on my car in order to put them into the physics spreadsheet. I've got some measurements but the relative location in 3D space is what's putting me off right now, and the fact that my car has: * a lopsided / asymmetrical lower front control arm * a multi-link rear lower suspension Some observations: * The X=0 in the suspension tab appears to be something inboard -- is this the vehicle center line? * The Y=0 appears to be the ground? * The Z=0 appears to be the vehicle center (front to rear)? Do all my numbers need to be in relation to these observations above? If so, what's the best way to determine the X=0 and Y=0 and Z=0 for my particular vehicle? I kind of have X=0 figured out and I think I can figure out Y=0 but Z=0 is the one that's more or less giving me pause. Where should Z=0 be, or does any of this matter? Here is a picture of the front lower control arm: https://photos.motoiq.com/MotoIQ/Project-Cars/Project-Lexus-SC300/i-tQSKtD6/A You can see that its asymmetrical. The front inboard mounting point is practically in-line with the ball joint but the rear inboard mounting point is far behind and isn't a straight line to the same point. For the purposes of modeling with the spreadsheets, should I just treat this like it's a pure A arm? Here's a (not very good) picture of the rear suspension: https://photos.motoiq.com/MotoIQ/Project-Cars/Project-Lexus-SC300/i-P6WW4zC/A There is a single lower control arm that's directly in-line with the spindle/ball joint. Then there are two other lower front arms. One controls the toe curve and the other basically operates in a straight line. If you scroll down here it appears to look a lot like the Art Morrison multi-link: https://www.hotrod.com/articles/art-morrison-multilink-irs/ Here is a blown up parts diagram: https://jp-carparts.com/toyota/partlist.php?maker=toyota&type=321140&cartype=4&fig=4804 The spreadsheet has "toe link" as a measurement -- I think that is exactly what I would do here? Other questions: * Inner steering is where the "ball" of the tie rod screws into the steering rack, I assume when the steering is zeroed? * Pushrod is the damper, and "inboard" is where it attaches to the chassis, and "outboard" is where it attaches to (in my case) the control arm, right? * Spindle is the center of the spindle? Would this be where the center of the wheel bearing is or something else? On the sample spreadsheet the spindle is offset from both the control arm points and the wheel center... * Wheel is where the wheel center is? * Turns lock is clear, but what is steer ratio? * 1/2 rack stroke - this would be the stroke of one side of the rack from full lock-to-lock? Thanks in advance!