Behind the driver's seat there is a trunk release that works with the ignition key.
There is a manual release behind the rear seat, fold the seat down to find it, than have someone push the trunk release button. If this dose not work it may be broken.
Usually they are in the glove box, but they could be located on the floor, in front of the seat, on the drivers side, or on the drivers door itself. The 1998 Buick Regal unfortunately does not have a manual trunk release. There are kits available to add a manual trunk release, however.
Glove Box
Owner's manual or keep looking. Maybe it does not have one. Look at the trunk lock and see if it is manual or electric.
There is an auto trunk release on a 2004 Grand Prix. If you push the drivers side door lock button to the left and hold it, the trunk will open.
NO, only button it has is on remote and manual open on trunk door, when car is unlocked.
Look in your owners manual.
Check in the glove compartment.
In the Mini Cooper, the keyhole to manually release the trunk is typically located near the license plate or on the trunk lid itself, depending on the model year. If your vehicle features a key fob, you can also use the trunk release button on the fob to open the trunk. Additionally, some models may have a manual release lever inside the car, usually near the driver's seat. If you're having trouble finding it, consult your owner's manual for specific instructions.
To open the trunk on a 1963 Thunderbird, locate the trunk release button, which is typically found on the dashboard to the left of the steering wheel. If the release button is not functioning, you can also open the trunk using the key; insert the key into the lock located on the trunk lid and turn it to unlock. Additionally, there may be a manual release lever inside the trunk for emergencies, but accessing it requires opening the trunk first.
Look in your owners manual and it should tell you.