For all but one refill where there was no Super Unleaded available I use Tesco Momentum, purely because SEAT recommend using the higher octane rating and I think being such a small engine it needs all the help it can get!
The manual at page 311 states that "at least" 95 octane should be used and that Super unleaded 98 octane plus is" recommended". Based on that and my fuel cap stating a minimum of 95 octane should be used, I shall continue as before with the recommended Super Unleaded. I am not knowledgeable enough to make a judgement that SEAT is wrong in their recommendation .
@supersnail - Having read that pages quoted I agree with you. The manual is not clear and indeed is contradictory. I take comfort in the footnote on page 311 "fuel with an octane rating higher than the one required by the engine can be used. I'll continue with the 98 octane but take comfort that if it's not available then 95 will do just fine