An Audi A6 SE 2.0 will be used to transport the new chairman of Powys County Council, Dai Davies.
The council made the decision, as it believed it would be better value for money.
But some councillors have disagreed, with Plaid Cymru councillor Elwyn Vaughan saying it is 'self importance gone wrong' and the purchase is insulting to staff and the taxpayer.
He said: "It is a total waste of money and insulting and insensitive to the people of Powys.
"At a time of austerity, continued cuts, communities losing services such action as this in purchasing a expensive car for the benefit of a single person is insensitive, insulting and shows total ignorance of the challenges many in our communities face.
“It is particularly insulting to staff, who only this week have been refused by the Tory Westminster government to have a pay increase beyond one per cent and yet see the chairman of the council who employs them have the luxury of a new executive car.
“It also undermines the image of being a county with a green heart and sustainable vision – yet driving around in luxury cars.
“If the chairman or any other officers need to go to civic functions then there are plenty of pool cars available within the authority that can be used, after all if they are good enough for staff they are good enough for councillors.
"Such action as this is nothing more than self-importance gone mad and we need a cultural change away from such attitude.”
A report on the decision making process behind the purchase revealed that, due to constraints in the members' budget, hiring a car was ruled out at being double the cost.
Lease was also ruled out, so the council decided to buy a car, and the purchase would mean the sale of the vehicle at the end of the chairman's term could be maximised.
The council compared a quote for the Audi, against a Skoda SE Tech 1.6, which is worth £10,000 less than the Audi.
However it argued the re-sale value of the Skoda is a lot less than that of the Skoda, and offers better value for money for the council.
Powys County council leader, Councillor Rosemarie Harris said: “The role of chairman of Powys Council requires a car to carry out civic duties effectively. The current chairman has special physical requirements which require specific adaptation that were not available on the previous vehicle.
“The council investigated a number of financial options including annual hire, lease and purchase, with outright purchase taken up because it was the most cost-effective and provided the best value for money for the authority.”
Montgomeryshire chairwoman Joy Jones, who is also the anti poverty champion at Powys, believes it sends out the wrong message to the taxpayer.
She added: "I'm not against the chairman having a car for his duties, but what I can't understand is that at a time of austerity, why does it have to be so expensive.
"We should be thinking about not overspending, and what this looks like to the public.
"There are pool cars that can be used at the council.
"The value of the car is two years worth of pay for some residents, and as anti-poverty champion the council has to be careful on what it spends."