FAQ/TROUBLE SHOOTING HINTS
Although my hopping and tire problems were due to ‘marbles’, a quick change to another set of F30s (under the eye of SM John B) reduced the problem but obviously did not eliminate it.
After the race I tore down my car and discovered that I had an almost invisible *Chassis crack* near the rear axle area. So under acceleration when my tires got grip they flexed the chassis and hence the Hop I was experiencing.