I have a question for all the mommies!?

Hey people, well on May 20 I had triplets-Autumn Sienna, Samantha Brookelynn, and Grayson Michael. YAY me! Well, here's my question for all of you mommies out there: My son was born with heart problems (like his daddy, according to my soon to be MIL) and although this is going away now, neither I or my fincee can get him to go to sleep unless he is driven around for a bit (which happens to be Greg's very loud and very old looking truck!) How can we get Grayson to sleep without using so much gasoline up in the meantime?