@RockPaperLizard 1. I'd go with Meguiars Endurance Tyre Gel, it does provide a subtle glossy black look but it will also help keep the rubber conditioned and prevent it drying out, used regularly it should help reduce the formation of the cracks 2. I use a combination of Autoglym leather cleaner and balm (available as a kit),[cont]

you can get more expensive leather conditioners/balms that are going to do a better job but they are significantly more expensive and the autoglym stuff hits the bang-per-buck sweet spot IMHO

@Pᴀᴜʟsᴛᴇʀ2 it's getting there isn't it? :)

@RockPaperLizard living in the UK, I didn't even realise these were problems that needed solving

We don't get cracket tirewalls, and the sun we get here really doesn't affect leather unless the car is ancient

@motosubatsu Thanks for the recommendations! I'll look into both of them.

@RoryAlsop Yes, the sidewall cracking is largely from the sun; the leather steering wheel issue is probably largely from the sun and possibly also from occasional wiping with non-leather cleaning supplies.

@RockPaperLizard yeah both of those things can seriously dry leather out :(