The engine coolant and the inverter coolant are two different systems on the Prius. Isn't there some savings when doing both together?

I didnt quite ask the question right previously. Am looking to buy an 09 prius that has some issues. Owner is finding water mixed with the oil and it has issues going up hills. Thats all i know.car is being sold cheap so am trying to figure out if its worth buying to fix it and using it as a commuter car. Thanks

Water is showing up in oil. Seller has not moved car since. Car has difficulty going up hills.

A/C blows cold for about 8 seconds, after start up, then cuts out, and air emitted is warm.
Happens every time. Mileage only 41K. Prius is still under extended warranty, and regularly serviced

Have read that an old battery (4+ years) can cause an MFD to not boot properly leading to all kinds of intermittent malfunctions. can anyone confirm?

Neither of fobs unlock and car does not start w/o fob inserted. Batteries have been checked. Have you heard of this and what is problem and cost?

The warning light and check engine light came on once so far and not since but a diagnostic reading from Jiffy Lube indicated the battery control module (PCA1F)issue. I don't know how serious this is or whether the diagnostic tool is reliable.

Am wondering whether to buy another one of these cars depending on repair prices.

After the light came on, the tire pressure light came on as well. After I put air in the tires, both lights went off. The other day the hybrid system malfunction light came on again. I needed to replace the front tires, so I thought that if I replaced them, the light might go off. I was right and it did a day later. Is there some sort of connection to the light that comes on and tire pressure, or are they completely unrelated?

It's time for my 25,000 mile scheduled maintenance and I have gone a bit over the 25,000. It will be about 25,400 when I bring it in. How much damage might I have done in those 400 miles? I am really concerned.

What would be the cost to replace the rear bumper?

Is it necessary to change between snow and summer tires, or just have all season?