It was a full on international meeting at the NEC.
Saw the mag article recently but can't remember the actual title (was a British GP I think but it might have been a Reedy race)
Was '89 or '90 I believe.
There was all sorts of fuss over tyres with many drivers moving over to foams and using additives. By the final day these had been banned but some were still using them. IIRC I think 7 of the top 10 in 4wd were disqualified