Warwick do regular one-off showcase basses in their Showroom section:
https://shop.warwick.de/en/Instruments/Electric+Basses/Warwick+Showroom
Most of them are more extravagant versions of standard basses, some are a bit experimental and out there while the odd one (like this) is pretty awful looking. You can buy it if you really want and have 5000 Euros to throw away, I wouldn't recommend it rhough.