If it's in the summer time, the heat from the engine may conduct through the walls and into your home. This would cause your home's A/C to over work and increase your electricity bill.
Trust me, I'm a bonafide guy who understands heat transfer.

 

The only issue I see is if you park a car already on fire in the garage, or if the garage is on fire and then you park a car not on fire in that said garage....

(FYI, this thread is hilarious... Keep em coming)

 

I know nothing can happen to the car...a stupid friend of mine with a diesel truck was implying that I hat to let it cool before putting it in the garage. I told him that I don't have turbos so I'm letting it run for a few min or parking it outside...I sometimes drive it like I stole it so the garage helps hide it from the police helicopter that's looking for me!

 

I once had a guy ask me, could you go to the parts room and ask for some canned steam.

 

As I laughed at this thread, I thought I should add, for those of us in the Great White North, it is currently -11(F) outside, so when I pull into the garage I open the hood on both cars and heat the garage.

 

^ This

And hide from all the people you flew by at mock 20 to get home so they don't call you in!

 

I would think leaving you car in the hot sun after driving in summer world be worse than pulling into a warm garage to cool. Either way, cars are meant to be exposed to the elements.

 

lol we had to have plug in block heaters for our cars. (Alaska)

 

Indiana here....Insulated finished garage, so in the summer I run my ceiling fans on low speed to circulate......in the winter I have a small fin tube heater that runs all the time. That helps with the heat from the both vehicles inside to keep dry out and keep ice off the floors, and ease of starting.

 

I throw ice made from spring water on mine, then blow it dry using a blow dryer with the eheating lements removed.

 

Poorly insulated house then. Trust me, I live in the "africa summers" of Florida.

I've been parking two cars in a garage since they were caves first.

 

You should also open the door from the garage that leads to the house to use that "free" heat.

My wife will leave the oven door open after we are finished cooking with it during the winter to utilize that free heat too.

Of course, we live in Florida, so if we get anything lower than 50 degrees (it's 84 right now), we consider that cold.

 

Don't you get out the Snorkel winter coat out at 55 down there Bucko?

 

Coats? We don't need no stinkin' coats!