Questions
"The state cops found the Porsche in the back of this allnight burger joint down in Lyons, and Ullman pulled a few strings to get it released to that lawyer. Then both of them ganged up on old Archer Houghton, which is the county coroner, and got him to change the verdict to accidental death. Heart attack. Now ole Archer's driving a Chrysler. I don't begrudge him. A man's got to take it where he finds it, especially when he starts gettin along in years."

Q 1: What's the meaning of 'A man's got to TAKE IT WHERE HE FINDS IT, especially when he starts GETTING ALONG in years.'?The two of them went on from many faculty parties, hitting the bars until they closed, then stopping at some mom 'n' pop store for a case of beer they would drink parked at the end of some back road. There were mornings when Jack would stumble into their leased house with dawn seeping into the sky and find Wendy and the baby asleep on the couch, Danny always on the inside, a tiny fist curled under the shelf of Wendy's jaw. He would look at them and the self-loathing would back up his throat in a bitter wave, even stronger than the taste of beer and cigarettes and martinis--martians, as Al called them. Those were the times that his mind would turn thoughtfully and sanely to the gun or the rope or the razor blade.

Q 2: What's the meaning of 'parked at the end of some back road'? I mean, what was parked at the end of some back road? ( the car they were driving was parked there OR that mom 'n' pop store was parked there? :P )

Question

Questions
"The state cops found the Porsche in the back of this allnight burger joint down in Lyons, and Ullman pulled a few strings to get it released to that lawyer. Then both of them ganged up on old Archer Houghton, which is the county coroner, and got him to change the verdict to accidental death. Heart attack. Now ole Archer's driving a Chrysler. I don't begrudge him. A man's got to take it where he finds it, especially when he starts gettin along in years."

Q 1: What's the meaning of 'A man's got to TAKE IT WHERE HE FINDS IT, especially when he starts GETTING ALONG in years.'?The two of them went on from many faculty parties, hitting the bars until they closed, then stopping at some mom 'n' pop store for a case of beer they would drink parked at the end of some back road. There were mornings when Jack would stumble into their leased house with dawn seeping into the sky and find Wendy and the baby asleep on the couch, Danny always on the inside, a tiny fist curled under the shelf of Wendy's jaw. He would look at them and the self-loathing would back up his throat in a bitter wave, even stronger than the taste of beer and cigarettes and martinis--martians, as Al called them. Those were the times that his mind would turn thoughtfully and sanely to the gun or the rope or the razor blade.

Q 2: What's the meaning of 'parked at the end of some back road'? I mean, what was parked at the end of some back road? ( the car they were driving was parked there OR that mom 'n' pop store was parked there? :P )

Answer

Q 1: What's the meaning of 
"'A man's got to TAKE IT WHERE HE FINDS IT,"
This means that a man has to take advantage of his opportunities, wherever he may find them.  It is a cynical statement though, because it implies that those opportunities might not be moral or ethical.

"especially when he starts GETTING ALONG in years.'?
This means that he is getting older, and the implication is that he is starting to notice his age, so it might be that he is no longer feeling 'young', or perhaps he is middle aged, for example, and therefore needing to think about things like his health, his situation in life, etc.

Q 2: What's the meaning of 'parked at the end of some back road'?
In this context, Jack and Wendy are parked in their car at the end of the road.  
Sometimes, we use "parked" to mean sat or "park" to sit, so you could say "park your self on that sofa".  It's more slang to use it in that way, though.

Answer

Hi Maggie!!

Q 1: What's the meaning of 'A man's got to TAKE IT WHERE HE FINDS IT, especially when he starts GETTING ALONG in years.'?

A man has to "get whatever he can" or "see an opportunity and take it"  does that make sense?
"getting along in years" means having a lot of years or getting older

Q 2: What's the meaning of 'parked at the end of some back road'? I mean, what was parked at the end of some back road? ( the car they were driving was parked there OR that mom 'n' pop store was parked there? :P )

the car that they were driving was parked.  CARS are parked, stores are not parked.