* Locksmith: This is the most reliable option. A locksmith has specialized tools to open the trunk without causing damage. They'll likely be able to get into the trunk without damaging the car's paint or locks.
* Roadside Assistance: If you have roadside assistance coverage (through your auto insurance or a separate plan), they can often send a locksmith or technician who can help.
* Dealing with the rear seat (if possible): Some models *might* allow access to the trunk through the rear seat, but the 1998 Buick Century is unlikely to have this feature. It's worth a quick check, but don't force anything.
* Do not attempt to force the trunk open: This will likely cause damage to the lock mechanism, paint, or surrounding areas. It will likely be more expensive to repair the damage than to call a professional.
In short: Call a locksmith or your roadside assistance provider. It's the safest and most cost-effective solution in the long run.