I vote for front seat covers. Just ordered two seat covers, a bungee holder and front floor mats! Can't wait to get my gear.
I'm still working on coming up with some way to do them that creates some more interest.
If we are selling one or less of each item we put on special it doesn't seem to be a big hit.
The smaller items get requested a lot but since they are generally less expensive a 10% or so discount doesn't amount to much for them.