Sometimes I pray in the car and sometimes I pray silently but I usually lose track of those prayers (add or something) and will start thinking of something else in my head. But, often, I do say quick prayers silently that keep an ongoing conversation going with God throughout the day (in those, I'm doing the talking--no listening really)
I try to have a quiet time with God each day. It is then that I pray aloud and from my heart. Not a memorized prayer or one from a book (which is OK IMO, but I think the relationship with God is strengthened if you say your own words.)
I often pour out my heart to God. It may be total appreciation, asking for help in coping with an issue or letting Him know what I am *really* feeling (ie. mad, sad etc.) I figure God knows what is in my heart so I'll just let it out--sometimes He gets both barrels.
Then, I always try to shut up to listen. And I know some people laugh, but God does answer. God does speak today.
I take my relationship to God very seriously. I GET to have a relationship with Him through Christ. I get to speak directly to Him instead of going through a High Priest. I think that is an awesome, awesome thing. But don't treat that relationship with enough respect or I would spend more time with God than I do. But I believe God knows my heart and knows my intentions.
I think showing your kids how to have a relationsip with God is THE most important thing you can do for your child. Show them it is a priority in your life and I think they may well turn to God more in their own lives.