I took my car down to the shop today to get an oil and lube job done and I go to pick it up and the mechanic said it was a little low on coolant and he checked for leaks couldn't find any. Also he checked the hoses and they were fine as well. He didn't fill it up with coolant because he said that Nissan requires a certain type of coolant...50/50 mixture and he recomends only using the Brand specifically designed for Nissan vehicles. He said the coolant level isn't critically low but the only problem I have is I live in rural Nevada and the nearest Nissan dealership is 63 miles away and none of the autoparts stores in town have that type of coolant, they recomended using the Prestone All Makes and Models but they didn't have the 50/50 mixture in stock. Mind you, I haven't dumped any coolant in my car as of yet. So here's my question why was the coolant a little low if there's no leaks or anything in it?