Apparently Senna was attempting to get more $$$'s out of Ron Dennis at the time & informed him he was going to check out the CART scene...the other theory as well, both he & Fittipaldi were close friends & Emmo had always promised Senna a chance to drive his CART Penske race car.
The fact both were sponsered by Marlboro didn't hinder matters either!
At the end of the day, Senna, although he was very interested in racing CART, the thought of racing at super speedways was not to his liking: the thought of racing with a possibility of hitting a wall at 220+ mph was not wise in his mind.
Memorable pics below.
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