I recently bought a Mini Cooper for my daughter. I did as my fatherand showed her how to change the tire - the unusual drop down small spare in the back. The tool kit was damp and the jack rusted until it was useless. Replaced everything and recently had a flat, when opened the well was still wet - some papers inside had mildewed.

Any ideas what's wrong? Where do I get a replacement jack/tool kit?

 

Sounds like you have a leak ... I'd get out the garden hose and a flashlight and start hosing it down and look for the water .... check the rear spoiler , rubber mouldings, rear wiper , and rear taillights ...

Jack ect would be a dealer part or a junkyard if you are lucky

 

One method i have used before is to turn the heater fan on full blast using outside air instead of recirc air That will pressurize the car's interior enough so you will sometimes see bubbles blowing out as you check the seals Bad Venge mentioned with a hose. Sort of like checking a leaky bicycle tube.

 

I think that you can used a hose. And this's very great.
rechargeable flashlight