The Mitsubishi Outlander containing the wheelchair was stolen from the drive of Christina Parsons, 34, and her family, who live on Newbury Lane, in Oldbury.
Christina's son Charlie Morley relied on the £3,000 wheelchair, which was tailor made for him, to get about.
He has been given a standard wheelchair in the wake of the theft but a fundraising campaign has been launched to buy him a new one.
The theft took place on Friday night with the incident captured on the family's CCTV.
Neighbours reported seeing the wheelchair dumped not far down the street over the weekend, however when the family went to look, it was gone.
Christina said: "I am really mortified to be honest. I didn't think anybody would steal our car or my son's wheelchair.
"For it to be stolen and left down the road, and stolen again, was terrible.
"Charlie has been really upset by it. It is his independence to go outside.
"He cannot walk so he just crawls in the house but he cannot do that outside. He has been really said about."
The temporary one that the family have been given is to allow Charlie to go to a hospital appointment."
West Midlands Police confirmed it was investigating the incident.
A spokesman for the force said: "We are investigating after a grey Mitsubishi Outlander was stolen in Newbury Lane, Oldbury at about 6pm on Friday, January 8.
"Anyone with information can contact us, quoting 20SW/7254X/21, via live chat at www.west-midlands.police.uk or call 101.
"Alternatively contact Crimestoppers anonymously on 0800 555 111."
To donate to the fundraising page, visit gofundme.com/f/charlie-for-a-new-wheelchair