I bought my new cooling expansion tank from Engel Imports.
$139.00 a lot better price than Partsgeek.com. It took care of my low level alarm light. I think the original float gets saturated with fluid and does not work properly. That is my opinion after used the car in summer & winter for 12 years. The new tank comes with cap and sensor installed.
I have a new sensor if some one needs one for half the price $35.00+ shipping.
My car runns great after 98,000 miles.