I heard that they wanted to keep pushing their brand message, and they figured test track was a worthy use of advertising money. They do reach a lot of consumers that way. GM’s loyalty towards EPCOT has certainly improved my view of them.
Auto makers go in way more for brand-awareness marketing than most other kinds of products.
People go years between buying cars, sometimes a decade or more.
While the dealerships run ads pushing you to show up on their lots for memorial day weekend, the manufactures play the long game trying to associate their brand with positive stuff in peoples minds over decades.*
Two things about this:
1) It's difficult to really judge the effectiveness in any single campaign like this. That makes it easy, in a lot of cases, to justify the spend or the cut of spend on one campaign or another when you've got a wide spread - a lot comes down to how people in positions in power feel personally about the connection.
2) Being that they've been with this pavilion so long, there could be the feeling that pulling out when they don't absolutely have to could create a negative perception in consumer's minds. "They used to sponsor this and then they couldn't afford to anymore" isn't what you want your customers thinking when you're trying to sell them one of the most expensive purchases most consumers make after a home... which isn't even a thing for a lot of people anymore, making a car
THE biggest purchase for many.
They'll be here for years to come to support you and your car, just like they've been here for decades in Epcot.
... and an add-on 3) ≈$10 million a year for a sponsorship is kind of a drop in the marketing budget of a major car maker. They'll spend
far more than that for a single super bowl ad, for instance.
The VIP room in the park they can send their executives to, dealers to, and top clients and partners to is also the kind of unique perk big companies like this enjoy having.
Another words, I'm sure someone in GM want's to keep it and I'm sure someone in GM is afraid to drop it** and therefore, we continue to have it.
* while not a major one-time purchase Coke is in a similar position as a long-term sponsor. They need you to keep drinking their stuff constantly in a market where it is easy to swtich so they spend a ton this way, too to give you all the positive feels and the last thing they want is Pepsi becoming the offical soft drink of anything if they can avoid it. I'm sure Budwiser would have been a long-term sponosor if the brands had aligned and in fact, one of their brands is a great example of how fragile that "relationship" they try to foster with their customers can be.
**last thing they want is Hyundai sponsoring Test Track 3.0