Lisense Disk

i purchased a mazda2 1.5 dynamic in jan 5th 2011 i went to renue my license disk in jan 2012 but was told that the car needed to go for road worthy to obtain a license disk . i phoned the salesman to ask what the problem was with  this disk story and i was advised to take the car for roadworthy myself i still did not reneuw my lisence disk as i feel why should i do all this ??? and want Mazda to do all this as its a brand new car Another thing that worried me was when i took the car for the first service they had to replace the two back shocks and sceem the from disk as it was faulty. at the second service i told the dealer that i still have a problem with one of the back shocks thats still noisy and the back bearing as well as the car's got a humming nois when i ride on the high ways so they told me that the tyres had a bad spot and its causing this but i was riding this car for the hole year of 2011 and no prob...      who can help me in this regard as it gives Mazda a bad name in the indistry and not the people doing the service.. please please can someone help in the regard Mr Hardien