My phone already has data, my car doesn’t need LTE.

Actually that's one arena of technology that should have taken a different course. Auto manufacturers should have an upgradable modem module that you can swap out with the latest "G" (as the modules are already self-contained) and the car should have antennae that cover as wide swath of the RF spectrum as possible. Cars are Faraday Cages. Cellular reception on a tiny little rectangle phone in your center console won't ever be as good as a dedicated modem and antenna. Also, the car's dedicated modem can transmit at higher power levels (up to 3 watts, vs a couple hundred milliwatts) so you'll get cellular reception in places your phone will just say no service. It also moves the higher-powered RF outside the car with the Faraday Cage shielding the human, for those that are concerned about such things. (Also, also, phones have to limit their total RF output to the sum of the current transmission rate of the radios, so when you're doing Bluetooth + cellular, the cellular modem won't be allowed to transmit at its maximum power level, further reducing range.)

Bonus points, there has literally been a Bluetooth SIM profile in existence for decades, although very few car modem have ever been designed to support it. This means, if this was implemented as standard, when the phone pairs with the car, the car inherits the cellular account of the phone while the car is turned on. So you're not paying for two cell bills, you get better reception, same phone number, better data speeds, better voice calling, etc. The phone also has supremely better battery life because it doesn't have to be constantly screaming at cell towers.

Of course, automakers and cell carriers would never implement these things that already exist because they'd eat into their precious profit margins.