[CMOTD]

Unfortunately the London tourist bus you have access to will not take you anywhere near slot car shops. Like any big city tour it just goes round the major tourist attractions in central London such as Big Ben etc. LINK You will only find flagship stores there such as Harrods who can afford the colossal rents.  There  is one major toy store in Regent Street - Hamleys - but I don't think they stock any slot cars these days. Proper hobby shops are found much further out. You would have to navigate the normal bus and/or underground network to get to Past Present toys.