I want manufacturers to be mandated to retrofit new technology to some portion existing vehicles. I have two 5-7yo Toyota hybrids and would love to have a bette

I want manufacturers to be mandated to retrofit new technology to some portion existing vehicles. I have two 5-7yo Toyota hybrids and would love to have a better battery technology to replace the NIMH batteries when the time comes. There are aftermarket Li-ion batteries, but I’d love a third party solution that would convert these into PHEVs. I only have a 8 mi per day commute, and would basically never need to buy gas with a PHEV. With one of these solid-state battery packs, I could even take longer trips all electric. I’d probably pay $15k per vehicle for this.