A couple of thoughts... Yes, patching the tire from the inside is much better. I do it myself when I have the time to take off the tire from the rim at home.. However, most repair places will refuse to do the inside patch. Once, I have even had a Cadillac dealer service manager tell me that they will ONLY put a plug in the tire for a flat...
In the old days, I carried a spare, and X tire iron, and a rolling hydraulic jack in my trunk. I just swapped the tire and was on my way. But I was young and strong then. Today, people don't want to work at changing a tire. They have insurance for a tow truck..
I have been driving for 40 years and can tell you the following about flat tires.... I have NEVER had a blowout or had an immediate flat tire while I was driving. ALMOST ALL flat tires are the result of a slow leak in the tire caused by a nail or screw that is stuck in the tire... If this is the case, or got flat while the car was parked, you can get home or to a garage with just a good 12v air compressor. Fill up the tire, and see if the tire stays filled for a few minutes. If yes, you can drive the car 3, 4, 5 miles and then check the tire again. I have often got home like this and fixed the tire at my convenience. You do not necessarily need to put in the tire slime if you have a flat tire.
If you fill up the tire and there is a noticeable leak, FORGET the Nissan slime. Buy a $10-15 bottle of GREEN SLIME at the auto parts store and use that. Then fill up the tire with air, and 98% of the time you will get home. The GREEN SLIME is a water-based product that is like jello, and will wash off easily and not hurt the inside of your tire.
SO - Use air compressor, check for leaks, if necessary use slime. Anything bigger call tow truck... Or do like me.. change the tire with a spare.