Don Swaim, a man who has interviewed a considerable number of authors, managed to talk with Burgess in 1985. It appears the entire recording, including Burgess sitting down in his chair and reciting a bit of French just before meeting up with Swaim, is available online.
A sample.
Q: You infuriated a good deal of people with your 99 novels list.
A: (calmly) Yes, that was the intention.
(There are also interviews with Isaac Asimov, Jimmy Breslin, Wlliam Burroughs, Dorris Lessing, Donald Westlake and Sloan Wilson.
The most entertaining interview on Swaim’s site (which includes dozens of writers besides those mentioned) is the one with James Purdy – not so much for what Purdy says as the way he says it, since he sounds a lot like Paul Lynde – maybe for a reason, since they grew up a few dozen miles apart in Ohio around the same time.