I believe the Garlits museum is on I-75 ????
I expect you will take Florida's Turnpike from I-75 over to I-4. It is a toll road as are several others in the Orlando area (408, 417, and 528). If you're going to be driving around the area on those roads (and they are absolutely the best way to get around), you may want to consider getting an 'E-Pass', available at any Publix grocery store. Lived in the Orlando area for over 15 years and never understood why folks would wait in those long lines to pay cash at the toll booths. I had an E-Pass within a week of moving there.
Drop me a note if you have E-Pass questions.
Tim