hey there!
i had interview there for fine art degree and it was easy, just speaking about your work, so I should think the foundation interview should be really easy. all my foundation interviews were a piece of cake compared to most of my degree ones. you should be fine. i'm coming to an end of my foundation at the arts institute at bournemouth, the intake here is 300, but it varies depending on where you study. i would suggest applying to bournemouth for foundation, one of the best places for the course, really good reputation. as for oxford brookes i dont hear about it being good art related, that is why im wondering about there for my degree. anyway, good luck with everything. xx