My younger DD has SPD, although we didn't know it at the time. She screamed nonstop any time she was in her car seat. When we had to make longer trips, we'd stop every hour to rest her lungs and our ears. It got much better when she turned one and we flipped her carseat around, although she still didn't like being strapped in.
She also didn't like to sleep. I could only get her to nap by putting her in the sling and walking up and down our street for 45 minutes or so. By the time she hit 17 months, she gave up napping entirely. She didn't need much sleep at night either, but at least with co-sleeping I could nurse her and mostly sleep at the same time.
Now, she actually sleeps longer and more soundly than she did as a baby or toddler. We only have going to bed issues every two or three weeks, so there is hope.
