CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income	$ 42,367	$ 1,912
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	2,341	1,551
Equity-based awards	2,205	818
(Gain) loss on asset disposals	(136)	90
Change in fair value of long-term warrant liability	0	(771)
Non-cash interest expense	393	3,307
Deferred income tax provision	1,787	0
Payment of acquisition contingent consideration	(5,520)	0
(Increase) decrease in assets:
Accounts receivable	(22,417)	(4,547)
Inventories	(30,551)	(56,039)
Prepaid expenses and other current assets	997	(4,495)
Deposits	(128)	(19)
Increase (decrease) in liabilities:
Accounts payable	12,971	2,273
Other payables and accrued expenses	5,480	251
Customer deposits	20,792	8,589
Net cash provided by (used in) operating activities	30,581	(47,080)
Cash flows from investing activities
Purchases of property and equipment and construction in progress	(5,126)	(3,392)
Proceeds from disposal of property and equipment	118	1,574
Cash used in acquisitions	(85,499)	0
Net cash used in investing activities	(90,507)	(1,818)
Cash flows from financing activities
Net borrowings from floor plan	55,751	68,886
Proceeds from long-term debt	30,000	35,155
Payments on long-term debt	(3,334)	(4,155)
Payments of debt issuance costs	(653)	(791)
Payments of initial public offering costs	0	(3,789)
Payments of september offering costs	(540)	0
Payment of acquisition contingent consideration	0	(1,457)
Distributions to redeemable preferred interest members	0	(90,503)
Proceeds from issuance of Class A common stock sold in initial public offering, net of underwriting discounts and commissions	0	59,234
Payments of tax withholdings for equity-based awards	(449)	0
Distributions to members	(1,520)	(4,206)
Net cash provided by financing activities	79,255	58,374
Net change in cash	19,329	9,476
Cash and restricted cash at beginning of period	68,153	11,492
Cash and restricted cash at end of period	87,482	20,968
Supplemental cash flow disclosures
Cash paid for interest	2,996	6,187
Cash paid for income taxes	7,480	0
Noncash items
Acquisition purchase price funded by seller notes payable	2,056	0
Acquisition purchase price funded by contingent consideration	5,482	0
Purchase of property and equipment funded by long-term debt	1,280	625
Offering costs, accrued not yet paid	$ 0	$ 600