Md. Code, Business Regulation § 18-101
(a) (1) This section does not apply to the laws that relate to the sale of alcoholic beverages.
(2) This section does not apply in Wicomico County.
(b) Subject to this section and § 3–704 of the Labor and Employment Article, a retail or wholesale establishment may do business on Sunday.
(c) Notwithstanding an agreement to the contrary between a merchant and landlord:
(1) the landlord may not directly or indirectly require the merchant to open the merchant’s place of business on Sunday; and
(2) a landlord may not directly or indirectly cancel or refuse to renew the merchant’s lease because the merchant refuses to open the merchant’s place of business on Sunday.
(d) Except in Howard, Montgomery, and Prince George’s counties, and except as provided in subsections (g), (h), and (i) of this section, a new or used car dealer may not sell, barter, deliver, give away, show, or offer for sale a motor vehicle or certificate of title for a motor vehicle on Sunday.
(e) In Anne Arundel County, a dealer may sell, barter, deliver, give away, show, or offer for sale on Sunday a new or used camping trailer, mobile home, or travel trailer, as those terms are defined in Title 11 of the Transportation Article.
(f) A new or used car dealer who violates subsection (d) of this section is guilty of a misdemeanor and, on conviction, is subject to a fine not exceeding $10,000.
(g) In Anne Arundel County, Baltimore County, Harford County, and Worcester County, a dealer may sell, barter, deliver, give away, show, or offer for sale a motorcycle, as defined in § 11–136 of the Transportation Article, or certificate of title for a motorcycle on Sunday.
(h) In Baltimore City, a used car dealer may sell, barter, deliver, give away, show, or offer for sale a motor vehicle or certificate of title for a motor vehicle on Sunday, instead of Saturday, if the dealer notifies the Motor Vehicle Administration in advance that the dealer intends to conduct business on Sunday, instead of Saturday.
(i) In Charles County, the County Commissioners, after a public hearing, may adopt an ordinance authorizing a new or used car dealer to sell, barter, deliver, give away, show, or offer for sale a motor vehicle or certificate of title for a motor vehicle on Sunday.