The original bloodhoundssc.com site had a lengthy description of the process the team used to identify and evaluate sites suitable for running a vehicle with the target speed, acceleration, and deceleration profiles they were targeting. At the time I thought it was a really interesting read. Unfortunately it isn't obviously available under the new bloodhoundlsr.com web site, but it might be available out there on the Intertubes.
I don't recall whether they mentioned or even looked at the Rann of Kutch, but if they did, they thought Hakskeenpan in the Northern Cape area of SA was a better choice, at least for their purposes.