why are the PARTS you need NEVER in stock?!

If you’ve ever been stuck waiting on a part and thought, “why is this part NOT in stock?!”

you’re not alone.

Let’s break down why it happens, what’s going on behind the counter, and what we can do to make it better as a team.

Here’s the truth: the Parts Department actually has most of what you need in stock. They just can’t possibly stock everything.

Think about how many makes, models, trims, and years we service. Now multiply that by every single part number that could wear out or break.

If the dealership tried to keep every one of those parts on the shelf, there wouldn’t be any space left in the building.

And every part sitting on a shelf represents real money the dealer has already spent. So the parts team has to make smart decisions about what to keep on hand and what to order as needed.

There are two main ways parts managers decide what to stock.

1. Gut Feeling
This is the old-school method. “We use a lot of these brake pads, better keep a few sets around.”
It’s based on experience but not always accurate.

2. Data and Demand
This is the smarter, modern method. The parts manager uses sales history to figure out what actually sells.

For example, they might say:

That might sound simple, but it depends on one big thing: tracking lost sales.

A lost sale happens anytime someone asks for a part and we don’t have it.

Let’s say you need rotors for a 2019 Civic and they’re not in stock. That’s one lost sale.

If that same part gets requested a few more times and still isn’t available, that’s how the system learns there’s demand — and that part gets added to inventory in the future.

If nobody reports the lost sale, the system never learns, and we all keep running into the same issue.

Here’s something most people in the shop don’t know: not all manufacturers let dealers return parts the same way.

When the dealership buys a part from the manufacturer and doesn’t end up using it, there’s no guarantee it can go back.

Here are a few examples of how that works:

1. Non-Returnable Parts
Some parts, like electrical items or special orders, can’t be returned at all. Once they’re bought, the dealership owns them.

2. Return Credit Systems
Many manufacturers use a credit system. The dealership earns “return credit” every month and can only send back a certain dollar amount of unused parts.
If you’ve got $20,000 of slow-moving stock but only $5,000 of return credit, you’re stuck with the rest.

3. RIM Programs (Retail Inventory Management)
Manufacturers like GM use RIM programs that protect certain parts the dealership orders.
If a part is ordered through the RIM system, it’s protected inventory — which means if it doesn’t sell, the manufacturer will buy it back or give full credit for up to 12 months.
It’s basically an insurance policy that lets parts managers stock more confidently.

And then you’ve got manufacturers like Toyota, which are more flexible in general.
Toyota allows returns on most parts for up to 12 months, which gives their parts managers much more freedom to stock aggressively and avoid shortages.

So when you wonder why your parts manager hesitates to bring in certain items, this might be the reason. They’re managing risk, cash flow, and return limits every single day.

Even the best parts departments can’t have everything on hand.
Parts numbers change. Supply chains shift. Return policies limit flexibility.

But when you understand the “why” behind it all, it’s easier to work together instead of getting frustrated.

So next time you’re waiting on a part, give your parts team a little grace — and maybe a quick “thanks.”
They’re juggling data, dollars, and deadlines every single day so you can keep cars moving.

Help your parts department by making sure they are reporting every lost sale.
When a part isn’t available, make sure it gets logged. That data helps parts stock smarter, fill gaps faster, and keep your bays turning.

Thanks for reading the DealerPlateGuy Newsletter.
Found it useful? Pass it on. Let’s change the industry together.

— DealerPlateGuy
Fixed Ops Director | Creator

“Making fun of an industry I’m trying to change.”