Mini R58 JCW with 100t km or Ford Fiesta VIII ST with 50t km

Hello together, I am looking forward to the decision to have a fun car. My everyday car is a Mini Cooper Countryman. The R58 JCW has always been my dream car. I find the current Fiesta ST very cool. I imagine to make trips with the car from time to time, maybe even road trips to other countries. Now I am faced with the choice: Should it be a Mini JCW with approx. 100,000 km, which I like extremely well and has a guarantee, or a Ford Fiesta ST with 50,000 km, also with guarantee? I rarely drive the MINI and would have the car fully covered in insurance. I also value a relatively inexpensive maintenance. I have looked at pretty much all reports about the ST and the Mini and still can not decide. Since I am also a big technical fan, I find the ST quite nice. The driving values look neatly too. Which car would you grab? Is the Mini already too old and vulnerable to technical problems? I don’t want to make a headache with the purchase. Thanks already!