Think they re-gas it
Anyway seen this offer for Air-con svc discount of 20%, don't know if it's again good though.
http://www.arnoldclark.com/servicing/servicing_repairs/vouchers/index.html
From thier website;
Why should I have my Air Conditioning System Serviced?
When the air conditioning system in your vehicle is left unused for a period of time unpleasant and sometimes unhealthy odours can occur, encouraging the onset of sore throats and allergic reactions. This is due to the condensation in your system combining with the heat from the vehicle engine to create an environment where bacteria & fungi can grow.
Also, overtime your system will leak refrigerant gas. This gas actually cools the air that enters the vehicle & circulates the oil which lubricates the compressor, therefore it is an essential part of the system and requires to be regularly refilled.
When the gas used within the air conditioning system escapes it causes the air conditioning to run inefficiently, making the compressor work harder and increasing your overall fuel consumption.
Regular servicing of your Air Conditioning not only helps to prevent illness & allergies, it also ensures your vehicle runs more efficiently and saves you money.
To save you even more money, we will discount the cost of a Full Air Conditioning Service by 20% - Print off the voucher and pass this to your local Arnold Clark or Machargs Service Reception to receive this exclusive discount.