if you plan on owning the van for a while then this is a bad  idea.
plastic cable ties have maybe a 5 year life.  metal  hog rings last forever.
theres a reason why auto mantufacturers dont  use plastic cable ties to
attach seat upholstry.

In a message dated 3/26/2017 4:06:18 P.M. Eastern Daylight Time,
ecaron1@COMCAST.NET writes:

and  those rings are going to have to now be cable ties.