Need some advice on car financing.

I am dead set on purchasing a grand am 'i have done alot of research on the grand ams and they seem to be really popular because you see ppl driving them everywhere and they were the staple for pontiac for many years and they were in the top 10 selling cars'. Well i have a choice between a two thousand three se sedan with 55k miles or a two thousand three se1 sedan with 59k miles. My bank that im financing with is willing to go up to 60 months on this vehicle and they both are around

9500. My bank told me that i am eliglble for 7.44 interest rate 'which is pretty low because i know some ppl that have as high as 23 percent interest rate' which means that my payments will only be about 178-180 a month. My questions are

1. Even if i go with the 60 month term 'which i know is a long time' is there anything wrong with me putting extra a month into the car when i can to pay it off a little quicker? i chose to go the longer term so my payments wont be as much but i will try to put a little more when i can.

2. ive noticed that some big name dealerships tend to have higher prices then other smaller dealerships. A salesman told me that the reason for this is because the big name dealerships cost more because if they have a really fancy setting, building that cost 4 million dollars to make then they end up jacking the car prices up higher. For eample, the place im going to be buying at is nothing fancy, hell they do business out of a trailer, but their prices are really good compared to the big dealers. My question is, could this be true to some extent? are they any advantages from buying from a small dealer as far as the price goes?

1. Do you think i did the right thing by financing through my bank? Ive heard alot of good things about financing from a bank. Ive heard that they dont pressure you, usually give you a better interest rate and dont try to rip you off on the price of the car. My bank goes up to 60 months at 7 percent interest because my bank doesnt even look at credit to calculate the interest, they go by the year and kind of car. But my bank did recommened that i find a dealer that sells at trade in value rather then retail value, do you think that is a good idea? Would you rather buy a car for the trade in value or the retail value? I looked up the cars worth on kelly blue book because it's important to not pay more then what a car is worth, that's where alot of dealerships rip you off.

2. Are etended warranties really worth it? They want to sell me a warranty that will add like 30 dollars to my payments a month. My question is are they worth it or wil it be cheaper just to take it to a mechanic? Because the car im getting does not have the factory warranty anymore.

1. Just because i find a car for say 9,000 at one place that is going for 11-13 thousand at other places does that mean that the cheaper price is not as good as the more epensive ones at other places? What i mean is say if i find a car going for 3-4 thousand less then other places at about the same miles does that mean that it's not as good as the more epensive ones?

Thank you so much and any help will be appreciated, sorry for all the questions.