As it is seen by the fiscus

Private car for business trips

A wholesaler sends its specialized seller to fairs within his/her working time. If the employee uses his/her own car for this, the boss will reimburse the costs without wage tax. 30 cents are due to the employee, naturally only from the 21st kilometer. However, he/she may calculate this amount in the income tax as propaganda (advertisement) cost. This formula also applies to the entrepreneur if he/she uses his/her own car for business trips. He/she can account for the costs through his/her own enterprise.