Hi there,
Were you clear-coating over paint you'd applied previously? If so, it's a common problem with recoating using enamel spray paints; I've encountered it before, though not to the degree it appears in your photo.
In spite of label instructions, I've found that recoating seems to work best within a short time (about 15 minutes or less, which is often per the label), or not until at least a couple of weeks later (which is also often per the label in many cases). If memory serves, I have tried topcoating with clear (same brand, same type of paint, per label instructions) within the recoat time, and experienced a 'wrinkle finish' effect, though not quite as pronounced as yours appears. Similar, though - as if the topcoat has somehow expanded and wrinkled to give the excess someplace to go. This has even happened to me long after parts have been dry.
Temperature is a factor, of course, but I've found recoating to be tricky business. I've pretty much settled on only recoating during that 15 minute window when using enamel, and not at all after that.
Also, I have used lacquer, and it does indeed harden quite a bit. In fact, I had some top plates I wanted to give a 'piano black' finish, and laid down a few coats of black plus clear over a primer base. After the parts were dry to handling, I had to pack them up for a move, and so wrapped them in masking paper and boxed them up. About a year later, I unpacked them, only to discover that the paint had been soft enough (and thick enough, I supposed) to have deformed a little bit where the masking paper had been folded, leaving impressions in the otherwise deep, glossy finish. I decided I needed to start over, whereupon I discovered that coating was unbelievably hard and tough - it took quite a bit time and effort with a belt sander to remove it.