Tried doing some more modelling yesterday. It's driving me up the wall at the moment. I'm not sure if the scan is bad, or the chassis on @Escape's car is crooked, but I just can't get any symmetry out of it. I'll have to verify some more measurements with a tape measure, with some luck it just did a bad correlation with combining scans, but all the lines look correct, the LH chassis rail is just at an angle and about 7mm out from what it should be according to RAVE
Also, Fusion really can't handle the huge mesh. Seemingly not helped by needing to push it to the cloud every time you save, which you have to do often in case it crashes. This is on my powerful laptop with an i7 7700K, 1060 (mobile) GPU, and 32GB RAM...
So any frustration from a potentially iffy mesh is amplified with frustration from Fusion constantly hanging.