I agree - every vehicle I've owned the maintainer has been wired directly to the battery... however... if you read the BMW forums there are a TON of posts specifically warning against doing this on BMW's with BMS systems (of which the B58/Supra has). Lots of anecdotal stories about issues...
I've owned a variety of exotics, most recently a Huracan. Honestly, I was tired of the attention - literally any time I would stop to get gas I would get mobbed by kids. Driving wasn't fun either because of all of the jackasses wanting to race or rolling down their window to make dumb comments...
The jb4 is a tried and well tested piggyback that has been used in thousands of cars. I would be hesitant to use any other due to it’s proven nature.
Yep, this is where my mechanic wired mine to. The three posts under the plastic cover are connected via a bus bar so you can connect the positive to any of the three bolts. Mine is on the second. Works great.
I can confirm that these DO NOT fit.
https://www.amazon.com/gp/product/B07MNVXR39/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
I am still searching for one that does.
Anyone know the best place (and price) to pick up the JB4? I know it can be purchased directly from Burger but I figure one of their dealers will be less expensive.