Mitsubishi Lancer 2008 Problems

While it's past history now, you shouldn't have accepted the car when the dealer hadn't done what they'd agreed to do. That should have been fair warning that the dealer wasn't as good as his word,  and you should have walked away. And never, repeat NEVER, do verbal deals. The rattle could be pre-ignition, but you need to have a mechanic check it for you, and a specialist in Evos would be  preferable. As for the dealer, you need to persist and show that you won't go away. Also consider going to the state consumer affairs people.

I would ask to speak to the dealer principal, the man who supposedly signed the letter, and request an explanation. If that fails to resolve the issue consider taking it to the consumer affairs people and get their advice.

You can have your car serviced by other service outlets without affecting your warranty, but you need to make sure the servicing will be according to Mitsubishi’s recommendation.

The first thing dealers usually do when they get a shuddering Jazz is to change the transmission fluid, which is a special fluid for the purpose, and that appears to fix most cars. In some cases it doesn't and in those cases it usually means the transmission needs replacing.  Trading the car is drastic, but if that eases your mind then so be it.

You’ve got the failure codes, so follow through on them and you should be able to establish the cause. Sounds like it could be a crankshaft sensor.

NOWHERE I'm afraid. When you modify a vehicle by fitting aftermarket springs you are deviating from the manufacturer's specification and taking responsibility for that modification yourself. You should talk to Lovells about any warranty they might have that might cover you. As for the concept cars, they are attention-grabbers that carmakers use at shows to increase traffic through their stands, and should not be taken to suggest you can do the same with your car and expect the maker to pick up the tab should anything go wrong.