The answers to the clues below will have something in common.

1. Illegal job site
2. Hit the roof
3. Illegal blow in boxing
4. Driving danger
5. Childbirth
6. Illegal trading site
7. Easy way to win a game
8. Checkup component

Answers:

1. BANK VAULT
2. BLOW A GASKET
3. BELOW THE BELT
4. BLIND SPOT
5. BLESSED EVENT
6. BLACK MARKET
7. BY DEFAULT
8. BLOOD COUNT 

HINT to what the answers have in common: 
It has to do with the beginning and ending letters. 

What the answers have in common:
Each phrase is a BLT sandwich. Each answer is surrounded by B - LT or BL -T.

Credit:  LA Times Crossword
 March 7, 2010
 Sabrina Walden
 DINER SANDWICHES