Hi MsA,
I have passed FAR, BEC, AUD - and I am waiting on REG. I took them in the order listed. I had several things that kept me motivated.
First, I was so scared of failing, I did want to take a chance, so I just studied as hard as I could until I burned out about 2 months before the exam, but I had done some reading and watched all the DVDs and made decent notes.
Second, I kept reading a motivational note that I had written for myself. You can find the link here: http://www.cpastories.com/2009/09/14/cpa-exam-motivation-tip-2-the-power-of-positive-thinking/ [sorry, I could not provide the document without giving you a link to my blog]
Third, people at work kept asking me when I would take the exam and if I was ready... and that made failure a horrible prospect.
Fourth, I had some goals that depended on my passing the exams...
Fifth, I prayed for motivation and guidance.
I procrastinated some, but not as much as I would otherwise have without those 5 things.
I hope this is helpful - and good luck.