Prince George's County Executive Parris Glendening, who was a member of the County Council that turned aside a police department request last fall for new police cars, said yesterday he will ask the council to approve a $2 million appropriation for new cars.

The money to buy about 200 new cars will be drawn from a projected $5.9 million surplus for fiscal 1982, he said. Glendening said he approved the purchase--initiated last fall by his predecessor, Lawrence J. Hogan--after reviewing "the context of our overall financial picture."

The county's financial picture is not good, however, as Glendening has previously said in projecting a $30 million 1983 deficit. That point was reiterated in one of two task force reports Glendening made public yesterday. The report made several recommendations that Glendening has already begun implementing, including an attempt at state legislation that would allow the county executive to impose a one-cent local sales tax.

While the budget committee's report "contains no surprises," Glendening said, "it is comforting to know that once the committee had the independent opportunity to ascertain the county's fiscal situation, they came to the same conclusion I did."

Recommendations of the other task force, which studied administration, intergovernmental activities, and regulation, included reducing stipends for persons who serve on boards and commissions. Stipends for the board of appeals and the personnel board, for example, would drop from $300 a month to $150.

The administrative task force also recommended changing the county's method of disposing of surplus schools. In the past, the county maintained a list of parties interested in buying school buildings, who were contacted by mail. The schools were not usually advertised until after a contract was under negotiation. The task force suggested advertising the availability of schools before negotiations begin.