anchor.diff:  1GA, Chevrolet
   1GB, Chevrolet
   1GC, Chevrolet
  -1GM, Pontiac 
  +1GM, Pontiac
   1GN, Chevrolet
   1GD, GMC
   1GE, Cadillac
  
positive.code: 935, Citroen
  936, Peugeot
  93H, Honda
  93R, Toyota 
  93U, Audi
  93Y, Renault
  9BF, Ford
  
negative.code: ZCG, Cagiva
  ZDC, Honda
  ZDF, Ferrari
  ZD0, Yamaha
  ZD3, Beta Motor
  ZD4, Aprilia
  ZDM, Ducati
  