2004 HYUNDAI ACCENT Power Trainautomatic Transmission Problems

I OWN A 2004 HYUNDAI ACCENT. FOR THE PAST 3 YEARS THE TRANSMISSION HAS HAD SIGNIFICANT ISSUES. THE AUTOMATIC TRANSMISSION WILL RANDOMLY SLAM INTO A LOWER GEAR OR WILL GET STUCK IN A GEAR. THIS CAUSES SAFETY ISSUES DURING WINTER DRIVING BECAUSE THE VEHICLE LURCHES FORWARD AT TIMES WHEN SHIFTING. WHILE ATTEMPTING TO ENTER INTO TRAFFIC, THE CAR WILL BE STUCK IN 3 GEAR WHICH ALMOST HAS CAUSED AN ACCIDENT SEVERAL TIMES BY PULLING OUT TOO SLOW. I HAVE HAD IT IN TWICE TO THE TRANSMISSION SHOP AND THEY COULD NOT DIAGNOSE THE PROBLEM WITHOUT AN ENGINE CODE. THEY FLUSHED, FILLED AND PUT A NEW FILTER IN THE TRANSMISSION BUT THIS DID NOT HELP. SOMETIMES THE CAR WILL WORK FINE FOR MONTHS OR A YEAR AT A TIME. I HAVE RESEARCHED THE PROBLEM ON THE INTERNET AND THERE SEEMS TO BE MANY OWNERS THAT HAVE VOICED SIMILAR CONCERNS. *TR

TRANSMISSION FAILED TO GO INTO OVERDRIVE WHILE TRYING TO PASS, DECELERATED FROM 65 TO 35, WENT IN NEUTRAL, THEN INTO A NORMAL GEAR. *NM

TRANSMISSION STARTED FAILING WITHIN THE FIRST 30 DAYS OF PURCHASE, EVER TIME IT WENT OVER 10 MPH IT LUGGED BACK AND THEN WENT FORWARD. BOUGHT THE CAR USED WITH 42K MILES AND THE SERVICE DEPARTMENT AT THE DEALERSHIP SAID THAT THEY WILL HAVE TO KEEL THE CAR TO REPLACE TRANSMISSION OR CHANGE A PART.