Depends on whether you are having heat issues, more useful on a turbo car, as helps keep under bonnet(intake) temps lower, can help in other ways too, like stops other nearby components melting down to the individual car really, but no downsides apart from cost, very unlikely to notice any difference on a n/a car though performance wise, could be good on rst's for example to keep some heat away from the starter if on downpipe for example.
tabetha