Can you purchase a warranty for a car when the warranty already expired?

Yes, but it would be around a thousand dollars. It would be better if you just put that money to the side in case you need a big repair.

Yes, you can purchase a warranty from a 3rd party.

Just google "extended warranty"

http://auto.howstuffworks.com/cg-extended-warranty-tips.htm

There are a number of companies that will issue a general warranty for newer model cars with reasonable records proving past maintenance work.
Be careful and read the fine print.

yes you can always buy an extended warranty. Make sure they cover the drive train. If the cost is high, I agree that you would be better off saving the money for any costly un forseen repairs. you need to weigh the pros and cons. The price of the warrenty, what it covers, what it doesn't cover.

Yes you can. ALWAYS buy an extended warranty from the manufacturer of your car. It may cost more than a 3rd party warranty But it will be very easy to get your car fixed without any of the stress of uncertainty or potential refusal to pay by the warranty company. 3rd parties are notorious for leaving you on the hook for most or all costs of the repairs.

But prepare yourself for what you need to do to get your car covered. You'll have to have the dealership inspect your car and do any standard maintenance necessary. They'll also inspect for prior mechanical, electrical or interior damage that could tried to be claimed once the warranty goes into effect.

As long as your car passes the inspection, you'll be able to get an authorized extended warranty from the manufacturer that will be a blessing if anything should break down later on.