if he is sleeping in a car bed I think that the first one kwite did would be perfect. if you are wanting to make one that will be more versatile I would go with a different pattern. you should find out what his favorite shape is, other than car. and maybe do a quilt like that. if it is stars maybe one with star blocks or if he likes circles maybe some of those really awesome quilts that have balls or circles on them. is his car bed toddler size or twin size? because that could make a difference on what pattern you will be making also.