I hate to tell, but this isn't going away any time soon. It will, however, get easier. Two year olds do need a little decision-making power to avoid the battle of the wills.
One thing I implemented that made life so much easier, was to avoid any negotiation by giving some choices right up front, eliminate "okay" from the end of my sentences (we aren't really asking for permission, right?), and use distraction and misdirection. Of course, some things are non-negotiable (like the car seat).
A couple of examples:
Either have him pick an outfit the night before...right down to socks and shoes. Or present him with two options. I don't even say anything like "time to get dressed"...just "do you want to wear this or this?" If there is any dawdling or tantrum...there is a time out and mommy chooses.
My almost three year old has decided that she doesn't want to wash her hands after going to the toilet. Since she already knows that it is the rules, rather than fight about it, I just ask if she wants the pink soap or the purple soap. It works almost every time.
In the car, should a melt-down occur, I start a little misdirection playing. If she is screaming that she wants a cookie (something she rarely gets anyway)...I start giving her silly choices. Like, do you want a big cookie or a little cookie. Is is pink or chartreuse? Does it have strips or polk-dots? Are the polk-dots big or small? Is it on a plate or a napkin? Is the plate on the table or the floor? And before you know it, the cookie is forgotten. The tantrum is over and both of us survive the commute home with a lot less stress.
This is a big time of adjustment, but it is also a time to really reinforce good behaviors and expectations. We have rules, such as a cup of water has to be finished between every cup of milk or juice. Less "nutritious" snacks are only available after naptime in the afternoon. But, otherwise, I don't make a big deal about what she eats. There have been days when all she eats is yogurt or bananas!
Sometimes, if there is initial resistance I just walk away for a few minutes and then come back to finish whatever it was that needed to happen. It is usually just them testing a bit. The less reaction, the better.