The basic rules on BIK for a Car are as follows:
The BIK value is calculated based on your annual mileage and the Original Market Value (OMV) of the car:
<15k - 30%
15,001 to 20K - 24%
20,001 to 25k - 18%
25,001 to 30k - 12%
>30,001 - 6%
So OMV (less anything your paid towards the cars purchase, but only allowed for the 1st year) * Percentage from above table = Benefit In Kind.
The BIK is then / by 365 * Days you have use of the car. I.e. you don't pay BIK for the days the car is not available to you or your family etc.
The remaining BIK value is then added to your Gross Pay for PAYE and PRSI, but removed from your Net Pay, as you recieve it in use of the car.
BTW: the OMV value does not reduce as the car gets older, so unless you are doing high millage it is not worth while getting a company car. You can get a deduction in the <15k - 30% rate if you meet a number of rules.
Towger