Stratus ES V6

• Automatic transmission
• 187,000 miles

I now have the heat fixed in my car, and now she sputters and cuts off if you don't push on the gas. It seems to happen more when driving for longer periods of time. we checked the air filter and when we put it back in the CHECK ENGINE light came on. The code was P0300 which means multiple misfires from more then one spark plug.
When we took the cap off, covering the spark plug;oil flicked out !! we replaced the air filter and the check engine light came off! but still the car would sputter and try to cut off. so we replaced 3 of the spark plug that ain't so hard to get at and the car was good for 2 days. Then the car acted up again! we brought her to a machanic but the car never acted up while we were there so he was unable to find the problem. With a little research on the internet I found things that may be wrong. Here they are.
Replace the valve cover gasket, and the seals for tubes, IGN wires, and spark plugs. Also the spark plug wires, distributor cap and rotor!!Now my biggest concern is, After paying all the money to get those things fixed what should I expect to go wrong after!!I know I'll never put a loan on a used car ever again!And I'll never buy a dodge stratus ever again!!!I can't wait to see what next month's problems will be for my peice of crap!