[spenner]

Inserts are a big part of car tuning now days...

If you are just bashing then any old insert will be fine, if you are racing then they can make a big difference.

There are currently a number of companies doing tyre inserts:

Mr O Foams
Trishbits
Rymart
Edit
Schumacher

I have recently started my own foam inserts which are under the Trishbits name.
I will be at the F3's this week and will have plenty of stock with me.

Hope this helps