Question: What vehicle was introduced in 1998 by Daimler AG as a City car which battery electric variant's field testing started in London in 2007?
Sentence (from "Plug-in electric vehicle"): A plug-in electric vehicle (PEV) is any motor vehicle that can be recharged from an external source of electricity, such as wall sockets, and the electricity stored in the rechargeable battery packs drives or contributes to drive the wheels.
Relevant evidence: No