CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
REVENUE:
TOTAL REVENUE	$ 4,236.7	$ 3,666.2	$ 12,684.1	$ 10,991.0
COST OF SALES:
TOTAL COST OF SALES	3,518.6	2,992.7	10,485.3	8,908.2
GROSS PROFIT	718.0	673.5	2,198.8	2,082.8
OPERATING EXPENSES:
Selling, general, and administrative	466.5	391.7	1,411.6	1,203.3
Depreciation and amortization	18.9	17.0	55.8	50.5
Asset impairments	0.0	0.0	135.4	0.0
INCOME FROM OPERATIONS	232.7	264.7	596.0	829.0
OTHER EXPENSES (INCOME):
Floor plan interest expense	22.3	0.0	66.1	1.5
Other interest expense, net	45.7	38.7	134.9	115.3
Gain on dealership divestitures	(5.0)	0.0	(8.6)	(13.5)
Total other expenses, net	63.0	38.7	192.4	103.3
INCOME BEFORE INCOME TAXES	169.7	226.0	403.6	725.7
Income tax expense	43.4	56.8	102.1	178.7
NET INCOME	$ 126.3	$ 169.2	$ 301.5	$ 547.0
Basic—
Net income (in dollars per share)	$ 6.40	$ 8.22	$ 15.03	$ 26.02
Diluted—
Net income (in dollars per share)	$ 6.37	$ 8.19	$ 14.99	$ 25.91
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic (in shares)	19.7	20.6	20.1	21.0
Diluted (in shares)	19.8	20.7	20.1	21.1
New vehicle
REVENUE:
TOTAL REVENUE	$ 2,163.5	$ 1,861.9	$ 6,392.6	$ 5,572.2
COST OF SALES:
TOTAL COST OF SALES	2,013.1	1,693.6	5,924.4	5,040.1
Used vehicle
REVENUE:
TOTAL REVENUE	1,294.7	1,111.7	3,959.6	3,345.6
COST OF SALES:
TOTAL COST OF SALES	1,235.3	1,049.6	3,767.3	3,135.6
Parts and service
REVENUE:
TOTAL REVENUE	593.1	526.5	1,764.3	1,568.2
COST OF SALES:
TOTAL COST OF SALES	256.0	235.3	753.2	702.9
Finance and insurance, net
REVENUE:
TOTAL REVENUE	185.4	166.1	567.5	505.0
COST OF SALES:
TOTAL COST OF SALES	$ 14.2	$ 14.1	$ 40.5	$ 29.6
Restricted stock
WEIGHTED AVERAGE SHARES OUTSTANDING:
Incremental common shares (in shares)	0.1	0.1	0.0	0.1
Performance share units
WEIGHTED AVERAGE SHARES OUTSTANDING:
Incremental common shares (in shares)	0.0	0.0	0.1	0.0

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