The way I see it, unless you can genuinely improve on a garment, it should be left as it is. The Trench Coat is one of the most classical, and must have, items of menswear.
Minotaur have taken a classic Trench and recreated the jacket from Poli-Flex Waterproof 3-Layer materials. Super minimal, but even more functional. Available now at Minotaur Shop with a retail price of ¥61,950 JPY (approx. $776 USD).