Have you ever called a car hot?

No, you are not the only one. Actually a pretty common term. It could have started from the term hot rod and crossed over to hot car. The origin of the term "hot rod" is unclear. For example, some claim that the term "hot" refers to the vehicle being stolen. Other origin stories include replacing the engine's camshaft or "rod" with a higher performance version. The term has broadened to apply to other items that are modified for a particular purpose, such as "hot-rodded amplifier".
hot
(hŏt)
adj. hot·ter, hot·test
1.
a. Having or giving off heat; capable of burning.
b. Being at a high temperature.
2. Being at or exhibiting a temperature that is higher than normal or desirable: a hot forehead.
3. Causing a burning sensation, as in the mouth; spicy: hot peppers; a hot curry.
4.
a. Charged or energized with electricity: a hot wire.
b. Radioactive or designed to use radioactive materials.
5.
a. Marked by intensity of emotion; ardent or fiery: a hot temper.
b. Having or displaying great enthusiasm; eager: hot for travel.
6.
a. Informal Arousing intense interest, excitement, or controversy: a hot new book; a hot topic.
b. Informal Marked by excited activity or energy: a hot week on the stock market.
c. Violent; raging: a hot battle.
7. Slang
a. Sexually attractive.
b. Sexually attracted; full of desire: In this week's show, the surgeon is really hot for the new intern.
c. Sexually aroused.
8. Slang
a. Recently stolen: a hot car.
b. Wanted by the police: a hot suspect.
9. Close to a successful solution or conclusion: hot on the trail.
10. Informal
a. Most recent; new or fresh: a hot news item; the hot fashions for fall.
b. Currently very popular or successful: one of the hottest young talents around.
c. Requiring immediate action or attention: a hot opportunity.
11. Slang Very good or impressive. Often used in the negative: I'm not so hot at math.
12. Slang Funny or absurd: told a hot one about the neighbors' dog.
13. Slang
a. Performing with great skill and daring: a hot drummer.
b. Having or characterized by repeated successes: a player who is on a hot streak.
c. Fast and responsive: a hot sports car.
d. Unusually lucky: hot at craps.
14. Music Of, relating to, or being an emotionally charged style of performance marked by strong rhythms andimprovisation: hot jazz.
15. Bold and bright.

From an online urban dictionary:
hot car
When a driver of the opposite sex as the passenger calibrates the heat settings in an automobile to full heat output, and positions all blowers to point in the general direction of the passenger.

Hot car is successfully reached when the occupant claims, "My skin is burning". Attempts by the passenger to re-calibrate heat settings to a more comfortable levelis met with a sturdy slap on the hand.
"That bitch whined about being cold so I pulled a hot car on her."

 

One or two prius with the 110v plug engine heaters have burned, I'd call them hot.
One or two teslas have burned, I'd call them hot also.

 

Yes. How old is your friend? Younger generations have the own "cool" lingo. About a decade ago, it was "sick". No idea what the cool kids are saying now.....

Also, posting this question in the Prime forum was definitely click-bait!

 

Obviously she never sat on an Oklahoma summer, sun warmed, vinyl seat in shorts.

Bob Wilson

 

Ya...I own two Prii in TX and that's the closest I will ever get to calling them "hot".

 

Certainly not about an Escalade! That's just a short, expensive school bus.