If you really think about it, you are being a total douche when you pray for anything
You are basically telling god... that you know what is best, more than god does
By praying, you are saying...
"Hey god, I know you don't want to give me a new car, but I want it anyway"
"Screw your perfect/divine plan god, I want a new car... me me me me me me, it's all about me"
If it is god's will... why are you trying to change god's will?
Do you really think you know better than god does?
Or, are people just selfish and don't care what god has planned?
You know sometimes when we are going through some challenges we always need someone to talk to right? Just put God in the position of that person to talk to. That is why we pray. Also, I am sure some situations are beyond us as well which may not be designed by God. I can list certain examples from my perspective as a Christian but praying is like asking God to help solve those situations beyond us. Sometimes, you need to ask to get result, you can't just keep quiet. After all, as a Christian, we have been asked to ask, seek and knock. Apparently you can only do those via prayer.