I have a Q5 built in 1998, which I understand is the last year before Modulus started putting truss rods in them. The neck was never supposed to "move," but it did. In 2005, the relief got so bad that it wasn't much fun to play and getting the intonation set correctly was impossible. I sent it back to Modulus for warranty work (the neck is warranted "for life" for the original owner only). I was hoping they would just swap out the neck for one with a truss rod, but they worked on the existing neck instead (which took several months). I later read somewhere (and I'm not sure whether it's true) that the bodies were custom fit to the necks (at least at one point), which could explain why they didn't just replace the neck.
Here's another reason to believe it isn't a one-in-a-million problem. At one point, I was thinking about trading it for something else, and consulted a dealer which will remain nameless but is well known to most of us (or at least those who frequent the internet). Their first question was, "is the neck straight?" That's not the question knowledgeable people ask when there isn't an issue.
Although it was hard getting Modulus' attention, they ultimately made it right. I mentioned the communication issue to my local shop, and their response was that Modulus has good people, but they are a small shop with everyone wearing a lot of hats, which sometimes makes them seem unresponsive. In other words, "keep at it, and they will come through."
Oh, and UPS damaged the hardshell case (but luckily not the bass) in transit. UPS (not Modulus) ended up buying me a new case, and a few weeks later listed my old one on e-bay in great condition (or words to that effect). You really had to look closely at the pictures they used to see the corners/feet knocked out and the related damage. Now there's a class act...