The Flying Squad by Edgar Wallace

SHE made her way down to the garage, put on the lights and examined the petrol tank before she threw open the doors and, knocking away the chocks, let the car roll of its own volition down the gentle incline to the mews. She closed the doors and took one quick survey left and right. There were two ways out, that which led into New Cavendish Street and that to the street that ran parallel. She decided on the latter route, sent the car quickly over the uneven paving of the mews, turned back to Portland Place and ran steadily and without check into Regent's Park.

She followed the Outer Circle, making the widest detour, until she came to Avenue Road, and a few minutes later she was speeding up Fitzjohn's Avenue to the Heath. The straight road to Oxford, which would take her through Maidenhead and Henley, she avoided, and came by a little-used road to Beaconsfield and Marlow.