Upvote:6
As of writing, there is no other requirement to enter France from within the European Economic Area (so including Spain but not the UK) than having a negative PCR test. Everybody is strongly encouraged to avoid traveling as much as possible but you are not legally required to justify the purpose of your trip or prove you are a resident as long as you stay within the EEA. There are additional restrictions for trips to Corsica, to French overseas territories and when coming from outside the EEA.
Once you are in France, the nightly curfew does apply to you and there is no blanket exception for long-distance travel by car. It's only allowed to be on the road during curfew (6 pm to 6 am) if you can show that your trip is essential (business that cannot be postponed, caring for a sick family member, etc.). You're also allowed to be outside of your residence for long-distance travel by plane, train or bus, for any purpose, as detailed on the form but, again, not if you are driving yourself long-distance.