I feel embarassed when friends go for a ride in my C5 and struggle with the seat belt.  It sits low, and is a real problem getting plugged in when you aren't used to it.  I don't have an issue, because I've used it enough times, but other do.  This is a handy extender to put on the passenger side to help others get buckled up safely.  Starting at $20 from Seatbelt Extender Pros.  They make them for all Corvettes all the way back to 1963, and in short stubby extenders like in the photo up to 15".  Might be what you need to occassionally strap that carseat into the car as well