>>1534695>>1534716>>1534717>>1534725>>1534727thanks all for the tips.
I found it, it's the anime Burn Up! Excess, episode 10.
It's a two-part story, starts in ep. 9 and ends in 10.
The "sentient tank" detail was specific enough, I went to TVTropes and there was a hint there:
>Burn Up! Excess has a two-parter episode in which the Warrior Team has to escort a military project that is, you guessed it, a super-advanced Hover Tank outfitted with an AI (codenamed Henry). It even falls in love with Rio and tries its hardest to protect her. It's a nice little horny anime.
