4 year old exploring her body

my 4 year old has always touch or tried touching her vagina with edges or the belt of her car seat i ask her if she’s itchy and tells me no how do i redirect her because i’ve brought it up to my husband about it and i told him i don’t want her to continue to do it thinking it feels good if somebody touches her somebody please help it’s a constant thing when we are in the car i hope i made sense