A spokesman said the improvements were “taken from the eyes of the consumer to instil faith” in used Daewoos and other makes.
“We carried out a broad review to make the used car buying experience nearer to the degree of service offered on new cars,” he added.
Three-year, unlimited mileage warranty extensions are available on all 'Known for Life' cars (those typically less than three years old which have a Daewoo service history).
The cover, which is administered by the AA, is identical to Daewoo's new car warranty.
“We also implemented changes so customers didn't feel they were being penalised if they bought a non-Daewoo model,” said the spokesman.
Non-Daewoos and cars without a full service history are supplied with an unlimited mileage, one year warranty which can be extended. Daewoo has also improved its vehicle exchange policy for cars with a quality or reliability problem.
In the past customers were only offered one replacement – if it had a problem, the owner had to live with it. Now, they receive replacements until the car is fault-free. Daewoo has also cut prices across the range. Two-year-old Nubiras and Leganzas, for example, have had their prices lowered typically by £500.