Think it may be best to seek professional advise link to the guide lines:
http://www.speed-trap.co.uk/Accused_...eedVSFines.htm
80 in a 40 and you could be facing a ban so good solicitor pleading your case may help. Summons can take up to 6 months to arrive so afraid it's a long stressful wait good luck and hope thinks turn round soon for you