Indiana Code Title 9. Motor Vehicles § 9-32-2.1-35

(1) With respect to a new motor vehicle dealer who plans to relocate the dealer's place of business in a county having a population of more than one hundred thousand (100,000), the area within a radius of six (6) miles of the intended site of the relocated dealer.  The six (6) mile distance shall be determined by measuring the distance between the nearest surveyed boundary of the existing new motor vehicle dealer's principal place of business and the nearest surveyed boundary line of the relocated new motor vehicle dealer's place of business.

(2) With respect to a:

the area within a radius of ten (10) miles of the intended site of the proposed or relocated dealer.  The ten (10) mile distance shall be determined by measuring the distance between the nearest surveyed boundary line of the existing new motor vehicle dealer's principal place of business and the nearest surveyed boundary line of the proposed or relocated new motor vehicle dealer's principal place of business.