Just three minor corrections:

It's Roger Penske, not Roger Pensky.

Roger Penske does not own CART, though he has been a major shareholder in it since its inception.

CART is generally considered to be more competitive than Formula 1, not less competitive. While it is true that the better drivers tend to gravitate to F1 this is more because of financial reasons than anything else. Due to the degree of technical sophistication and development necessary to be competitive in Formula 1, it's been pretty much a two-team show (Ferrari and MacLaren) for the past several years, even though there are 12 or 13 teams that have been competing. Due to the wide technology gaps between the F1 teams, the drivers rarely get to showcase their abilities.

CART is currently a publicly traded company. CART's stock ticker is MPH. It first went public in 1998 at which point all franchise owners were issued shares and an IPO was made. After the IPO CART used some of the funds to purchase the Toyota Atlantic and Indy Lights racing series, and now there is a CART ladder system for developing drivers in lesser formulas and bringing them to CART Champ Cars (currently known as the FedEx Championship Series). CART is technically a sanctioning body.

It's also worth noting that while Mario Andretti did return to CART after driving in Formula 1 for some years, he had driven in the predecessor to CART/IndyCar years before going to F1. At that time the racing series was generally referred to as the USAC Gold Crown series.