This is set after Mabel and Dipper have already gone back to Piedmont, but before the Pines twins classic set off on their own adventures. Just to clarify.
Stan was still snickering to himself as they returned to the shack.
"Shut up," Ford growled, shoving his (larger than average on account of his extra finger) hands into his coat pockets after slamming the car door.
"I'm just impressed, that's all," Stan said with a smug grin, following his twin back towards the house. "I don't think I've heard of anyone failing the driver's test in such a…" he fumbled for the perfect nerd word his brother would understand, "spectacular way before."
"I haven't had to drive in around thirty years, okay?! I'm out of practice!" he protested, feeling his face reddening.
"I still taught a bear how to drive better than you!"
Ford gave Stan a long look over his shoulder, before shaking his head. "Not even going to ask."
"Just remember, you can take the test again in seven days," Stan reminded him cheerfully as they went inside. "Assuming they haven't decided to ban you from the DMV, of course."
In hindsight, maybe sending the car (Stan had refused to let him use the Stanmobile for the test so he and Fiddleford had repaired one from the dump) skidding around the street corner on two wheels to avoid that truck had been a bad idea, but he'd calculated perfectly, and after crashing through that fence and rolling down the side of the hill he'd managed to land them right-side up. It wasn't his fault the vehicle had been a lot less durable than the star cruiser he'd had to steal once (which, come to think of it, hadn't managed to end up intact either)…
He was stopped from storming off to the basement (to lose himself in research, of course; definitely not to sulk in any way, shape or form) by his brother's voice asking tentatively, "It...wasn't because you were having flashbacks, was it?"
Stanley was giving him his 'I'm trying not to be too openly concerned because I don't want you to feel crowded or patronized' expression, head tilted and eyes troubled behind their spectacles.
Ford stopped glowering and tried to smile reassuringly.
"Only a little bit at the beginning. Mostly I just forgot how to use a stick shift." And, well, he kept trying to press buttons and dials that weren't there, weren't even necessary for this type of vehicle.
It was enough to satisfy Stan. Who proceeded to saunter forward, eyebrows bouncing, and say, "Sounds like you need someone to give you lessons…"
Ford sighed, rolling his eyes.
"Yes, Stanley, I would like you to re-teach me how to drive, please."
"Yes!" His twin's fists shot up into the air, and for a moment he looked like he might do a victory dance or something.
Ford sighed again, more loudly.
"Aw, don't be like that, Poindexter. It's not every day I get the opportunity to be the one teaching you something." Before he knew it, he was being pulled into a quick headlock (which he could escape from if he wanted to, of course, but what the heck) and his hair was being ruffled by affectionate noogying. Ford pulled himself free after a few seconds and punched Stan in the arm, leading to a quick and friendly punch fight.
By the time they decided to pretend they were mature adults again and got dinner started, Ford had forgotten about any desire he might have to sulk.