The $400 million in Tesla trucks story is well known, though the news changes very quickly here.

From Feb. 12:
State Dept. Plans $400 Million Purchase of Armored Tesla Cybertrucks

From Feb. 13
State Department halts plan to buy $400M worth of armored vehicles from Musk’s Tesla

From Feb. 26
Tesla’s $400 million armored EV US gov contract was indeed shady

A discussion that happened during the Biden administration but wasn't the size and scope mentioned. From the third link

Sources familiar with the talks with Tesla under the Biden administration told NPR that there were discussions about armoring electric vehicles, and a budget of less than $500,000 was set for 2025 for it:

The person said the State Department and Tesla had agreed during the Biden administration to conduct research about armoring electric vehicles, but no money had been set aside to purchase armored Teslas for the State Department. A total budget of $483,000 had been approved to buy light-duty EVs as possible State Department vehicles. That plan was moving forward as recently as November 2024.

The NPR story actually says:

But NPR has obtained a State Department document detailing that Biden's State Department planned to spend just $483,000 in the 2025 fiscal year on buying electric vehicles and $3 million for supporting equipment, like charging stations. It represented less than 1% of the hundreds of millions of dollars likely destined for Tesla vehicles after the Trump administration quietly revised a State Department procurement document.