Welcome Nanosm!

Let's evaluate your situation as working with local keyphrases can be a bit different.
You mentioned that the terms you were optimizing for included:
auto repair warren township nj
auto repair springfield nj
auto repair morris county nj
#1 - Is this the way the phrases appeared in your keyword research results? Identically as listed above... [auto repair warren township nj] and [auto repair springfied nj] etc? Or...
#2 - Is [auto repair] the term you're optimizing for and you've just tacked on the cities to the end of the term?
I ask because you handle it two different ways.
If #1 is the case, you will do better to use the keyphrases exactly as they appeared in your keyword research results. That means working in [auto repair springfield, nj] and the other terms individually most of the time. You can also use the words within the phrase individually a time or two. This can be complicated to do and still maintain a natural flow unless you get creative with your keyword use.
For example, break the term up. Just as an example, "something, something, something when you need
auto repair. Springfield, NJ is a convenient location. Drop your car off before work.............." Punctuation (actual punctuation, not general symbols) has no affect on the term. Search engines read right through it as if it weren't there.
If #2 is the case, you've got a lot more freedom. You can use [auto repair] completely separately from the cities/counties. This way you could do one section of the page that lists your locations (springfield, warren township, etc.) and maybe a second one at the bottom of the page with contact info for each location.
Hope that helps!