The good news first: You can always deduct your business travel for tax purposes. You can still use your car privately. However, vehicle taxation is complicated. The tax office knows several variations of taxation, so you can not always choose according to your taste. The starting point for taxation is whether your car is classified as a private car or a company car.
Here are the principles: If you use your car more than 50% for work, then your wheelset must be a company asset. If operational use is less than 10%, there is always private assets. If the vehicle is used between 10% and 50% for business purposes, you can choose whether to classify the vehicle as a business asset or as a private asset.
And this is how business trips are deducted: With a private car, business trips can be deducted at the flat rate of 30 cents per kilometre. In the case of a company car, the costs incurred are entirely operating expenses, but any private use based on the logbook method or the 1% method must be offset against the operating income.