During the summer months I try to attend a number of classic car shows with one of the cars. For the last few years, I've been taking the Firenza to shows, and before that the Sportshatch. They're a good place to meet up with other enthusiasts, as well as a source for parts when there's an autojumble.
Many classic car shows are held in the grounds of stately homes, which make a nice backdrop. Venues in the north west include Tatton Park, Weston Park and Cholmondeley Castle. Other shows are held in motorsport-related places, such as Shelsley Walsh or Oulton Park. But in most cases, the show is made by the people who bring their cars to display, or those who come to see them.
The normal show season runs from April to September, with a small number of autojumbles or larger shows outside that time. My cars are only taxed for the summer months as they are not eligible for free road tax due to their age, so this coincides quite nicely with the season.