The Quahog Mattress Center is where Peter and Lois go to look over mattresses in "Guy, Robot".
After finding out the salesman is sleeping on an air mattress in a friend's basement, they decide not to bother with his recommendations and check things out for themselves. Peter messily makes himself at home on a mattress, before he and Lois decide it is the one they want. But rather than buy the one they tried, they order the same mattress from Amazon and have to race home to beat the drone which passes the store to deliver it. Peter tells the flabbergasted salesman that real stores suck as he rushes out.