Chapter $25-$ Honest Air Conditioning & Heating, Inc. Case

Cory Babcock and Honest Air Conditioning bought a Corvette from Cox Chevrolet. Their retail installment sales contract $($RISC$)$ required monthly payments until $$52,516\mathrm{.}20$ was paid.

Cox assigned the RISC to General Motors Acceptance Corp. $($GMAC$).$ The buyers then sold the car to Florida Auto Brokers, which agreed to pay the balance due on the RISC. The check to GMAC for this amount was dishonored for insufficient funds, however, after the vehicle's title had been forwarded.

GMAC filed a suit against Honest Air and Babcock for breach of contract. Babcock and Honest Air argued the RISC was a negotiable instrument. Who is correct?