Just a couple of throwaway ideas, being as how I don't have the connections to get them into production... and, hey, maybe they exist and I just haven't seen them.
I've got a double-walled (so, somewhat insulated) plastic cup with its own swirly straw. It has a standard-sized base, to fit a standard automotive cup holder. So far, so good. But! Being regular-soda-sized on the outside, it's quite small on the inside, so filling it with ice & water in the morning doesn't keep me supplied with cold sippin' water for the day... not even to lunchtime. How about making these things in large & jumbo sizes, keeping the standard base dimensions?
Relatedly: is anyone making a car with Peltier modules in the console cupholders? Wouldn't it be nice to have the ability to keep drinks cold, or hot, or one of each? If automotive consoles were of standardized dimensions, this could be an aftermarket item, but I fear it really needs t be a factory goody.