London vintage shops  

Just click on links,then...
Just click on links,then vintage dealers then choose UK.

kempton
If you can get there, and if its on when you are in London, Kempton Antiques Market (2nd and last Tuesdays of each month) is very good for mid century.

Pimlico road ? Ebury Street...
Pimlico road ? Ebury Street for high end dealers
Alfies antique market has lots of booths and there are lots of shops on the road across from it but it is also quite pricey.
The old cinema in Chiswich is nice and seemed more reasonable pricewise.

London vintage shops
Thanks for everyone's input. I looked at the links, but so many of them are online only or require prior arrangements. Any car boot sale places that are good for mid-century would also interest me. cheers!

Depends on what you are looking for
Like Killian suggested, Church St and Alfie's Antique Market is a great place to start.
Lots of Danish Vintage shops in town too. My favourites are:
Førest, in Clerkenwell (next to Magma bookshop which is worth a look)
The Modern Warehouse, in East London
Elliot & Tate, in East London
Two Columbia Rd, in Shoreditch
Drop me a line if you need any specific info. Happy to help: danielmpoole@yahoo.com

London
Cheers, Daniel, I checked out your list and they look promising. I'm so disappointed I arrive too late to see 100% Design and London Design Week!!

South London
Hello, I'd like to add the following to Daniel's excellent list in case you happen to be in South London on your trip.
Crystal Palace (on the Overground line linked to Shoreditch and Dalston) has quite a range of vintage shops. Designs of Modernity, Matt Mitchell London and ID for London - all listed on the Design Addict links - are based in the area, and there are interesting vintage curios, as well as fantastic coffee, at Bambinos.
Hope you enjoy your stay.

This should be of interest too
If you are in town between 18-22nd September:
http://thedesignjunction.co.uk/