I try to fit my machine and bag between the front and back seats on the floor. Put needle down and foot down and plenty of padding around machine. If it has to go in the trunk, boot, then at right angles to way you mentioned ie sides of bag pointing to front and back. Then use suitcase to hold tight I have also used bungy ties to hook on handles. You don't need bad roads emergency stop recently put the handle of my bernina under the top cover.