I didn't have any interest in him but he had a car
I hope you're joking, what was so great about the car?
Maybe it was because I was lazy that day. I can't be bothered to walk.
You shouldn't lead people on just because they have something you want. They will think that you are into them for other reasons.
I'm going to take him to a movie in a few days. I'm expecting him to buy me a drink.
They could be really upset if they find out you are using them. Using people is really low eventually you will get caught and have a bad reputation.