booster-pad car seat suitable for a van?

[BEAUTlFUL]

dh drives a van, with one of those passenger seats in the front that is two seats together.

is it safe for DS (5yo) to sit in passenger seat on a booster pad? obv with seatbelt on!

thanks! x

you know what i mean by booster pad... the car seat without a back or arms on it.

not a copy of yellow pages or anything.

he is safer in a high back booster.