yes, mrfred..you gonna have to do the chop like everyone else here who has plastic windows
If you don't:
-overtime, it will leave a 1" or 2" rip in either mid corners or middle of the plastic windoe
-if the weather is cold and you didn't do the chop, it might crack the plastic
There's a lot of topic here regarding your concern. Search the thread "Plastic Window or Chop"
Here are some of them to keep you inform but not to scare you
*a new owner thread that didn't know about the chop*
New owner, didn't know about "chop", window seam ripped...
*what happen when it's cold but sunny outside thread*
Cracked Plastic
*Plastic Window dilema*
plastic window headache