Looking for a heater for my mini-barn for my outdoor car?

It seems that you mean cat, not car. If I wanted a heater for a room a cat was in, I'd probably use an oil-filled radiator type. All electric heaters use the same amount of power to heat a certain space from a certain temperature to a certain temperature. It's just how electricity works.

The difference between infrared and other types of heat is that infrared heats objects or people, or cats, not the air around the heater. It's the same thing as what you get from standing in front of a fire. You are warmed by the fire if you're standing in front of it. Move away, or stand with something between you and the fire, and all of a sudden you don't feel the heat from the fire. It's also called radiant heat and is the same as we get from the sun. That kind of heater does eventually warm a room, because the objects it heats give off that heat into the room.

Considering that all you really want to heat is the cat, not an entire room, I'd look at providing a small heated space for the cat. Cats are very good at finding a warm spot if they want one.

A simple incandescent lamp shining down on a small area might warm it enough for the cat to be warmer. Put a cardboard or wooden box somewhere, open at the top and one side, put a blanket or some straw in it, fix the lamp so it shines directly into the box from a few feet away, far enough to be sure it can't set fire to what's in the box, and if the cat sleeps under the lamp he'll be toasty. Also make sure the lamp can't be knocked down. A hanging lamp or clamp lamp would be best and if it was a clamp lamp I would secure it with something else as well as with the clamp. I have such an arrangement in my kitchen, a lamp that shines directly down onto a counter from 2 feet away. I put my bread under it to rise.

That section of counter gets warm to the touch after a while.

There are heat lamps made for when people want to keep chickens warm

There are heated beds for cats.

You might want to check out this site: http://www.shopthecoop.com/

LOL yes CAT not CAR , I just got one of my bigger carrier crates and put a couple thick cotton towels around it to keep the heat in around the vents and put a towel down in the crate and a bunch of old cotton shirts and ordered a pet thermal bed that is supposed to keep their heat in which ill put on top of the bedding, lets hope that works ok, thanks for the reply

A heating pad inside a box, under some towels would be safe and inexpensive to operate.