Car rental protection offered by rental companies can cost $15 to $30 a day—in 10 days, that could be as much as whopping $300. Alternatively, a credit card with rental insurance will offer the same coverage at no extra cost—and even if it does, it's significantly cheaper than what rental companies offer. 

For example, The Platinum Card® from American Express charges a flat fee of $19.95 or $24.95 per rental period (not per day) for primary coverage.

The eclipse is happening in a week, and unfortunately I have no choice but to travel between Charleston, South Carolina--an eclipse viewing hotspot--and Atlanta, Georgia on August 23, just two days after the momentous event that's drawing an estimated crowd of one million+ visitors to the coastal city.