Looking on the internet deeply has found these results:

on the spot is the most popular phrase on the web.

in the spot 133,800,000 results on the web	on the spot 1141,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
(Oskar) there's a red sedan outside, Parked in the spot closest to the door. And just like that, Mike found himself in the spot I was in not so long ago. Being in the spot light even for one night makes me nervous. Made in the spot where Mr. Clutter was murdered. I'm an adjunct professor and I believe you parked in the spot reserved for my Segway. So if he didn't park in the spot... He's home at last, Mom, in the spot we always saved for him. However, more than half of the production is sold in the spot market.	Because they are putting you on the spot. Many children who ran, were killed on the spot. With devolution, stricter financial controls can be applied on the spot by the delegations. The financial controller may carry out checks on the spot. I put the Master of Baidley rather on the spot yesterday. I should have trusted my instincts and killed you on the spot. We did so immediately, on the spot. The data submitted by the sole fully cooperating Japanese producer were verified on the spot.

in the spot

133,800,000 results on the web

on the spot

1141,000,000 results on the web

More popular!

(Oskar) there's a red sedan outside, Parked in the spot closest to the door.
And just like that, Mike found himself in the spot I was in not so long ago.
Being in the spot light even for one night makes me nervous.
Made in the spot where Mr. Clutter was murdered.
I'm an adjunct professor and I believe you parked in the spot reserved for my Segway.
So if he didn't park in the spot...
He's home at last, Mom, in the spot we always saved for him.
However, more than half of the production is sold in the spot market.

Because they are putting you on the spot.
Many children who ran, were killed on the spot.
With devolution, stricter financial controls can be applied on the spot by the delegations.
The financial controller may carry out checks on the spot.
I put the Master of Baidley rather on the spot yesterday.
I should have trusted my instincts and killed you on the spot.
We did so immediately, on the spot.
The data submitted by the sole fully cooperating Japanese producer were verified on the spot.