I was on Etsy and randomly found super cute fleece seatbelt covers this lady was making to look like little foxes. I asked her if she could make custom Shiba ones if I sent her some picks and details. She said yes and they turned out really cute. I told her I'd let the forum know as I know many of us can't resist all things Shiba. If you're interested at all, here's her shop:
http://www.etsy.com/shop/AreYouStuffed

If you're interested, message her and ask her to do Shiba seatbelt covers. She'll create a custom listing for you. I paid $22+$2 shipping.

She did a really great job and I love having them in my car. My seatbelt was always digging into my neck and these prevent that. They also weren't too hot to use in summer despite being made of fleece (I bought these in July and have been super delinquent in letting you guys know about these fun car accessories).