I'm not convinced that Lexus are even bothered about pushing the brand in the UK.
I don't think we can say that the F product is better than the German equivalents - just different. It could be argued that M cars have better steering and AMGs generate sounds that we can only dream of. Reliability - Lexus is of course top!
I don't think the IS-F will ever be a classic. They are great cars, but most petrol heads don't even know they exist. Add the other nail to the coffin in the fact that the IS-F is so understated. It is very unlikely that someone will spot an IS-F and think 'I want one of those!!!'. It's hardly a self promoting vehicle! A real shame.
Long term I think the IS-F will become a very expensive beast to run. When warranties run out and things start to fail, there won't be an abundance of parts available - unlike the equivalent M or AMG. As for indies...... forget it!
We may see the bottom end of the IS-F market on Autotrader at £13k, but realistically cars are probably already trading at less than £10k.