on mine you can really see the heat coming out from the now gap, and it runs a hell of alot cooler. they do work!
i agree some cars they dont look good on but some they do. its all personal preference really like everything, each to their own aye. plus some cars need to have them out of nessesity (i know i spelt that wrong) because of the engine and or pipework to clear under the bonnet, zvh in a ka for example.