I agree, I use TeslaFi all the time and it is great for tracking trips, charging and the like and quite cheap (I can give you a referral code to make it even cheaper). It would be great for business trips and road trips, since it can collect multiple drives and charges into a single trip report. Since it also collects odometer reading you can see actual mileage driven.
I actually use it in preference over the Tesla app to check location, range, charging rate etc. because then it won't wake the car if it is sleeping and can see the history rather than just a snapshot right now. It's also integrated with Alexa and so I can warm/cool the car or check the range with a voice command while putting my shoes on!
Even has vehicle range/battery degradation reports and latest software updates info if you're keen on that. It will collect data once a minute unless the car is sleeping (in which case it just gets the current status without any other details to check if the vehicle has woken up, so doesn't cause any overnight battery drain).
I don't understand other's security concerns about such sites, TeslaFi has two-factor authentication, so your account is unlikely to get hacked and what are they going to learn anyway? That I went to the store everyday last week? Who cares! My life's not that exciting.
