You have a choice, but be careful about it. If your next "newest" card is a long time after the best buy, then KEEP the best buy card. Use it once every 5 months for a small purchase and pay it off immediately. If your still thin on credit history, I'd keep it.
If you aren't going to by anything requiring credit {car, house} in the near future, then your score can 'repair' after closing hit you take, and then you can close it if you have a next newest card right along behind it or have about 5 years of credit history with another card...if NOT, I'd keep it OPEN and use it as noted above so they don't close it on you.
On the last hand, if there is no BB near you and you don't order online for them, and the car is useless totally to you, then close ti,just be aware of the hit you'll take.
Its up to you.
Best of luck in your wise decision.