Compact Char-g as available from shops is basically an English language package and instructions, 2.2 motor powered car witha choice of two frequencies (27 + 40MHz).
Bit Char-G is Japanese/Asian market cars, there’s more car choice, more frequencies available (35 + 57 + 45 + 27MHz) and 3 different motor combinations available.
Parts will interchange between the two cars as they and mechnically indentical. So you can buy a Compact Char-G from K-Mart for example and then use hot-up parts from ausmicro.com to get better performance!