"I bought myself a spanking new car".
That's what Steed told Mrs Gale in series 3 Don't Look Behind You.
It's a 3 litre Lagonda supercharged vintage car with 85 PS. The car model was built between 1930 and 1933, but the production year of Steed's Lagonda is 1930.
According to Michael Richardson's book Bowler Hats and Kinky Boots. The Unofficial and Unauthorized Guide to The Avengers, (2014) it's a 1930 Lagonda 3 litre, which was first registered 21 October 1930 and still registered in 2013.
Despite the Italian sound of the name, Lagonda was a British automobile manufacturer.
Steed arrives at Cathy's flat to invite Mrs Gale for a run with the new car and intents to find out what the vintage car will do. He insists on driving her the long way down to Exmoor to Sir Cavaliers Resagne's mansion.
"Can't think of anything nicer - you at my site...wind catching at your cheek...wild flowers in your hair". He's not teasing this time - he stops the car on their way to Devon to pick some flowers for Mrs Gale during the ride. And he promises her they will have lunch and a glass of port at a wayside inn.
In the The Avengers Steed drove a few times with Mrs Gale, but most of the time in her car such as in Warlock or Propellant 23. He asked her to give him a lift back to London in Six Hands Across a Table.
1930 Lagonda 3 Litre
Licence plate: GK 3295