with my new BL Destiny, I bought their hard-sided luggage... a little pricey, but it is lined with foam shaped exactly like the machine to protect the machine from any vibrations that might harm the electronics. when i went to class, two other ladies just used the destiny's cloth cover that came with the machine and rolled the machine in a fold-up wagon similar to this one
http://www.walmart.com/ip/Westfield-...-Blue/34109012 ... seems pretty nifty. but i would worry about bumping the machine taking it in and out of the car, etc. and still with vibrations. many years ago, i transported a much less expensive machine in a regular rolling suitcase but had two pieces of firm-ish foam around it.