i do have a habit to put on seat belt for my girl whether it's a short distance or not.
same tots as you, i let my girl sit on my lap in the car which i feel more secure.
by the time, i wanted her to be in infant car seat, was too late . she was refusing.
until now, she's 2yo still sitting on my lap.
i remember i read about putting on these seat belts be it a car or a stroller first before moving out.
then it's will become a routine that the car or stroller will get moving only after the seat belts on.
same theory for those ppl who want to train their kids to sit in a stroller then can move out to go shopping. but this one i've failed.