If you're thinking of buying an electric car any time soon, you'd better place your order before President Biden signs the Democrats' big climate, tax and health care package into law — which could happen as soon as this weekend.

Why it matters: Democrats initially hoped to dramatically increase EV adoption via the bill, called the Inflation Reduction Act, by expanding the existing consumer tax credits for battery-powered vehicles.

Driving the news: To get Manchin to go along with the broader bill, the rest of the Senate Democrats agreed that only cars with batteries containing a certain percentage of materials sourced from North America or U.S. trading partners will qualify for the credits moving forward — even though that doesn't align with manufacturing reality.

Where it stands: EV buyers are currently eligible to receive a federal tax credit of up to $7,500, but the benefit is capped at 200,000 vehicles per manufacturer.

What's new: The new bill would eliminate the manufacturer cap starting in 2023. But only vehicles under a certain price ($80,000 for trucks and SUVs, or $55,000 for all other vehicles) would qualify.

Zoom out: To pass the new bill, Senate Democrats needed to be fully unified — giving Manchin lots of leverage to extract concessions.

What they're saying: "The $7,500 credit might exist on paper, but no vehicles will qualify for this purchase incentive over the next few years," John Bozzella, the Alliance for Automotive Innovation's president and CEO, writes in a blog post.

Yes, but: People will buy EVs even without federal tax credits — especially if gas prices stay relatively high — but only if they're available. Inventories are tight, and prices are rising sharply.

What's next: The House of Representatives is expected to approve the bill Friday and quickly send it to Biden's desk. After that, figuring out which vehicles will qualify for what portion of the tax credit over time will take some doing.

The bottom line: Lots of unknowns remain about this legislation's consumer impact.