If the cambelt and water pump have not been changed then it is fine as long as you don't wait until it does go (could help with price negotiation.
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Tyres are very selective, everyone on here has their favourites, I use Vredesteins and think they are great, very good grip in all weather types.
And finally (in reverse order actually) I would not advise flashing at other drivers at all, if you want them to come through then just sit tight and if they want to they will come through. (nothing worse than flashing someone and they pull out regardless of other traffic and have a crash, have been warned that they can try to blame the person who flashed them, and other similar, yet daft stories, but don't want to give them an opportunity.