I've been in this situation twice, first time, driving my '73 Squareback
showing off my newly restored optional "world champion" VW wheels, suddenly I
noticed some loud noise, while I felt the car jiggle. I pulled over, only to
find that all four wheels were loose, even though I tightened them firmly.

The second time this happened to me was when driving the maiden voyage in my
friends freshly $20000 restored '64 bug. We were doing about 80 km/h (50 mph)
when I noticed some strange noise and vibration. While letting off the gas
pedal, I suddenly recognized the symptom, and stood on the brakes, only to see
the left rear hubcap came rolling past us. All five bolts had come off, the
wheel was hanging off the axle nut, with the top of the tire tucked into the
top of the fender. We started searching for the lost bolts, found only three,
and loaned on from another wheel. The three remaining wheels were loose, too.

Both of these incidents happened because of the same reason, freshly painted
wheels. When first installed, we tightened the bolts as far as possible, but
when driving, the paint under the contact area of the bolt started to work
itself off, and the bolts loosened. Next time I paint wheels, I am removing the
paint in the contact area before mounting the wheels.

PerL
88 Syncro