If the red bus is 48 feet long, the orange car is 48/4 = <<48/4=12>>12 feet long.
Since the length of the orange car is 3.5 times shorter than a yellow bus, the yellow bus is 3.5*12 = <<3.5*12=42>>42 feet long.
If sitting next to each other, the driver of the yellow car will see 48-42 = <<48-42=6>>6 feet of the red bus.
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