The two missing words in this verse differ by a single letter. The first word has seven letters, and the second has six. SHOW and SOW are cuewords - meaning they stand for the answer words. Notice that the cuewords also differ by a single letter.

A brand new car, Dad? What a SHOW!
You even SOW the radio!

Answers:

PRESENT
PRESET

Credit:
The Enigma
NPL Magazine - February, 2015
LEXMAN