4 inch, 4x6, and 6x9
3 1/2 inch
The rear speakers on a 1999 Buick Regal are removed by accessing the speakers from the trunk. The mounting bolts and then removed, the wires disconnected, and the speakers lowered from their mounts.
no
The rear deck is two 6x9's. The front door panels are 5 1/4" and the tweeters are 1/2 inch.
Regal tangs get about 12" long.
The 2004 Buick Regal has a 3.8 L base engine size.
The 2012 Buick Regal has a 2.4 L base engine size.
The 2001 Buick Regal has a 3.8 L base engine size.
The 2013 Buick Regal has a 2.4 L base engine size.
The 2014 Buick Regal has a 2.0 L base engine size.
The 2011 Buick Regal has a 2.4 L base engine size.