Cruze and Fiesta are popular cars that dealers probably have little to no trouble getting sold so don't expect to get a huge discount.
Also, you might have better luck getting the dealer to throw in extras/package upgrades rather than actually lower the sale price of the car. When I bought my car in 2008 I got it for $8k under MSRP (and I think only about $900 over invoice) and got free splash guards, illuminated door sills, trunk mat and cargo net, and professional tinting.
