Can bailiffs take cars that's used to transport disabled people?

No

The goods of the debtor are exempt goods include a vehicle on which a valid disabled person’s badge is displayed because it is used for, or in relation to which there are reasonable grounds for believing that it is used for, the carriage of a disabled person.^[1]

If a bailiff takes control of an exempt vehicle, the debtor can make a claim to exempt goods.^[2][3]

^{[1] Regulation 4(1)(d) of the Taking Control of Goods Regulations 2013
[2] Civil Procedure Rule 85.8
[3] See Making a claim to exempt goods}