Why will my car only start sometimes?

I have a 1994 oldsmobile cutlass. Sometimes it starts other times it will just click so I try turning the key couple times and it will finally start. Also around the same time my cruise control will and will not work,it has a mind of its own. Also the transmission sometimes wont shift into overdrive. And now sometimes I have to manually blink my blinkers. The car has a mind of its own, and all this started to act up around the same time. I took it to two different mechanic shop and they both said everything looks fine and I have to take it back when it acts up. Well more then likely when i bring it back it will be fine again. CAN SOMEONE PLEASE HELP ME!!!!!??????