Elijah’s mother, Onessa, said: “I am appealing to everyone to keep an eye out for Elijah’s lifeline. This is not just a vehicle, it is our road to freedom. Without it, our poor boy cannot see in his final days.
“This vehicle cannot be easily replaced and it is his 14th birthday in a few short days.
“We had hoped to take him away with his medical team to enjoy the surroundings of the countryside which he loves so much.”
Sergeant Adam Hunter said officers are conducting house-to-house inquiries and trawling through CCTV footage.
“Time is of the essence,” he added.
Anyone with information is urged to call 101, quoting 01/141980/24. If they want to remain anonymous, they can contact charity Crimestoppers on 0800 555 111.