Waterloo Classics has been a regular informal gathering for owners of a wide range of interesting cars on the third Saturday of each month. See the website:
http://waterlooclassics.com/ . When I went last month it was all very agreeable. Parking in Lower Marsh, on the southern side of Waterloo Station was easy by virtue of some helpful person putting up cones to reserve spaces for an eclectic mixture of cars. All it needs is more Lancias!
Colin
