Isofix seat fixings

[Joe2.0E]

I wouldn't bother with the plastic guides unless you are struggling to find the isofix points. The Child Seat base will make indentations in the leather if the child seats are fitted long term but they are a necessary evil.
A good quality child seat like a Recaro won't have any rough edges underneath.
You can get protectors that fit like a rubber mat under the child seat but I've never used them personally.