To be honest, this was the first episode I ever saw of Curb Your Enthusiasm, I really liked how cleverly plotted the situations were with inadequate cash, attempts at polite reasoning that fail dramatically, and even the little fight between Melissa (the person who always goes ahead of Larry) to get to the doctor's office first.
The basic premise: Every action has a consequence, no matter how small it is. This makes and drives the episode (and possibly the series) to the brilliance in comedy that it is.
An example involves Larry failing to hold the elevator door for the Asian toll booth attendant (named Joanna) due to the policy at the doctor's office of "First come, First serve". This causes her to grow suspicion that Larry does not want to pay her back the money he owes her from the last time he met her when he failed to pay his toll exiting the parkade at the toll booth.
The secondary premise: Policies and standard practice are virtually everywhere, making more reason for Larry to try to reason on why that is, causing sometimes more trouble rather than helping the situation.
An example is Diane Keaton leaving a message for Larry on a answering machine asking for him to call her back, the phone number she described was incomplete due to cellular dropouts. He was just introduced to a Interior Decorator that also had Diane Keaton as a client, Larry tries to ask her about Diane's number and tries his best to politely reason out the information. Unfortunately, once she told him it was standard practice that she couldn't give out her number due to privacy reasons, Larry can no longer reason with it and fires her.
The only other episode that I think even came close to the quality of the writing in this one that I have seen so far was "The TiVo Guy". This is without a doubt in my opinion one of the top episodes of this series. Although I have not finished watching Season 4 (6 episodes in) and haven't started on Season 5, I'm pretty sure this and "The TiVo Guy" will stick as my all-time favorites.