Problems with 2002 Buick Rendezvous VEHICLE SPEED CONTROL

When driving our car accelerates while driving. doesn't matter what speed, 25 and or up, it's frightening and not sure of where to go or who to see. *tr

5 minutes after being on the highway at 70 miles per hour the vehicle started dropping speed and message center started showing low battery, lights problem, service engine soon, brake fluid low, windshield wiper fluid low, low tire pressure, security service. also, when i come to a stop the engine shuts off by itself as a low power, few minutes later, starts back up and can keep driving but hitting the gas pedal and releasing it after a few seconds at a time to recharge the battery so it would not shut off again. also, after this happened the emergency lights began to come on and off by themselves. took to a mechanic to have it serviced they said to replace the battery and alternator and if problems continued the starter. few months later after replacing these parts, it started giving me problems with low fan as if the relays were bad but they are in good condition, low battery fuel and had to be changed again because the battery was not retaining charge. the vehicle still has all the messages in the message center, they never went away. then within the last month i wanted to have the radio replaced, but i found out the speakers have power coming straight from the battery to the radio that causes it to overheat and makes static when the radio is on while driving. also, the neutral safety switch for the ignition key got burned so now it is not working but still has allowed for the car to turn on and off and dry. a week ago, 04/28/14 the vehicle has been showing an error message in the message center, every light possible in the message center about the services that need to be done come on, which i assume now is the body control module that has gone bad. most frequent message is security. gas gauge goes up and down and never gives an accurate reading of how much is in the vehicle. *tr

Car is reluctant to move at low speeds (25/30 mph). gear moves very reluctantly into higher gear. hear loud cluttering noises from gear box, metals grinding against each other. this causes slowing the traffic and feel as if someone will hit me from behind. feel unsafe to drive. safety issue. *tr

I was parking my car in the parking lot of a bank. the accelerator stuck and my car bumped into the post at the end of the parking spot. *la

The cruise control light on the instrument panel would come on and flash when the vehicle was not in cruise control (but was being driven on the highway). i checked to see if maybe the cruise swtitch had been left on; it had not been. turning the switch on and off did nothing -- the cruise did not work and the light flashed. i checked the vehicle owner's manual and it did not state the reason why this light would flash -- i had to assume it was doing so because the cruise was broken on the vehicle. took the vehicle into the dealer and sure enough, the cruise switch was bad. the owner manual should have contained information on what to do when the light was flashing.*ak

While driving on highway at 65mph vehicle would not accelerate and car slowed down. dealer contacted, said it was caused by transmission shaft pump having a defect. *ak