There was some talk on the GBS Facebook group about the sump sticking out (about 40mm) below the chassis and people looking into options for having it shortened.

It seems there are 2 camps of people: Speaking to GBS, they have had their Mazda demonstrator for a number of years, it's been tracked and worked hard and the sump is fine... Some people fatally smashed their sump the first time they drove their car!

There are a couple of services out there from the likes of KitCar direct. A couple of horror stories about welded sumps leaking and the added complication of it being a really poorly casted ally, probably mostly filler chalk! This is generally what it comes back looking like. The oil pickup tube has to be modified too. Just a smidge beyond what can be done easily at home!

Anyway, we decided to have the sump off and have sent it off to GBS. They don't offer this service yet, but are going to give ours a go - and if successful, start offering it as a service.

The refitting can now be found here.