Hot Splash was a radio show on Shibuya FM which noodles co-hosted about once a month from 2006 to 2011. This was a talk show where they discussed noodles' music and concerts as well as various other topics.
An episode of Hot Splash was uploaded to noodles' Youtube. Check it out on the videos page under the "noodles talk" section (it is seperated in parts 1 and 2). Audios of the episodes were available (and might still be available) on the Shibuya FM official website. Note that the show is in Japanese and, as far as I know, English translations have not been provided anywhere.
If you have any more information about Hot Splash, or if you are able to provide English translations of the show, please fill me in so I can post more about it! Visit the submissions page or email me at firstname.lastname@example.org.