I have always let Harley ride upfront with me and have really begun worrying about it. Am I a bad mom for letting him stay up there with me?

I tried letting him ride in the back seat once and he pooped, puked and pee'd..

All within only 2 miles or so of my house.. I don't have a car seat for him bc my bf is almost always in the car with us too so I don't have the head rest part of the seat to attach it to. What do you guys think I should do?