The reason you can't find that vehicle in a list of cars is because it's not a car!
The Mitsubishi L200 is (for road tax purposes) a 'Light Goods Vehicle'. If it was registered between March 2003 and December 2006, it qualifies as 'Euro 4 compliant', with annual tax of just �120. Otherwise the tax is �180 per year for any LGV registered from March 2001 onwards. (LGVs registered prior to March 2001 are taxed at �120pa with an engine size below 1550cc or �185pa for larger engines).
See here:
http://www.l200.org.uk/community/index.php?top ic=10225.msg81041