Almost trafficked or just a coincidence?

My two friends and I were in Spain last summer and we took a taxi to a shopping mall about 20 minutes outside the city. On the way there, the driver (35 ish) was very friendly. He asked what we had done so far, how long we were staying, and gave us tips about the city. Nothing sus so far. Before dropping us off, he gave us his card with his phone number and said we could call him when we were done, because there are usually no taxis available when the mall closes.

Later when the mall closed, we saw that there were indeed no taxis outside. We called him, and he arrived after about 10 minutes.

When we got into the car, he did not turn on the taxi meter. We joked in our own language that maybe we were about to get kidnapped. He was talkative and friendly at first, but after 15 min I noticed we were no longer on the highway. Instead, we were on a very dark, forest road. It was late at night, and ahead of us there was a car parked as if it was waiting. This was not the same road we came from. In just a matter of a few minutes all of this happened:

I told my friends to look at where we were, and we all went quiet. The driver seemed to notice that we got nervous, so he also stopped talking. Then we saw a police car behind us with sirens, and we thought we might be “saved” from something that was about to happen. The taxi driver then said, “If the police stop us, I will tell them you are my friends.” I asked, “Why?” He seemed stressed. The police car passed without stopping us.

A few minutes later, he dropped us off outside our hotel. When we asked how much we owed him, he said nothing and told us we could just go.

There was no taxi meter, his comment about the police, the strange route, and then not wanting payment. Was this all just a coincidence, or does this sound suspicious?