O2 Sensor problems of the 2005 Saturn ION

We bought this used Saturn on 12/ 28/13 after driving about 10 days, the engine light came out. The warranty auto mechanic said the electrical issue. The auto sale dealer checked it was oxygen sensor issue. Referred us to get free fix at the el monte smog auto mechanic but failed to fix it despite many times. We went to the mechanic near our house. We paid several hundreds to fix the problem. Few weeks later, another problem that the key could not take out from the switch and it always stuck inside the switch soon after we turned off the key. We need to wait a long time to pull the key from the switch. We ignored the issue but went to make a copy from a locksmith in alhambra. We used the duplicated key to drive it but it was stuck and couldn't take out. We went back the locksmith who helped us to remove the key from the switch. Since then, the issue was solved . On 4/5/2014 we got oil change and was told there're many issues that need to be fixed. It costed us about $1200- . Few days later, the engine light came out again, we scared that it was unsafe as everyday we need to drive carpool from home (chino hills) to our workplace . We were told it was oxygen sensor again. On 4/14/14, the window screen wiper suddenly moved while we were driving. It could not stop at all even after we turned off and turned out the key. The next day, it had run out the battery and triple a said it was the electrical issue. We went to another auto mechanic who told us that it was the computer issue as the ge had installed their computer to attached most of the parts including the wiper. 2 days ago, we heard a strange sound on the driver side while driving to work on the freeway. I slowed down the speed. We were so worried to drive the car . We regret to buy american car as we used to buy japanese cars. Please advise . Victim of Saturn car william tong & ada tong MA.