how can I make him cum

My bf doesn't cum  a lot. When he cum it's little by little and it doesn't turn me on. I want us to have a great time every time we have sex. I want him to cum like never before but idk what to do to make him cum alot and make his super hard. Help me any advice on what I should do. Btw we only have sex in his car and tricks or hot stuff I should know.