According to this site; http://www.carandclassic.co.uk/car/C03962 the XJ40 XJ12 were introduced in March 1993 and made until August 1994 and that only 1200 were made, making it fairly rare. Wikipedia says that the XJ12 was made until the end of the 1994 model year (model year not actual year, new model years seem to start in the autumn).