Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Cash Flows [Abstract]
Net loss	$ (39,879)	$ (6,552)	$ (12,678)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization expense	3,257	195	260
Impairment – property and equipment	108	0	0
Amortization and accretion - marketable securities	2,465	0	0
Depreciation – lease vehicles	106	146	244
Loss on disposition of property and equipment	0	0	321
Gain on marketable securities	0	(36)	0
Provision for doubtful accounts	233	40	(14)
Stock-based compensation expense	51,121	45	113
Change in fair value of Merger warrants liability	(32,733)	0	0
Change in fair value of historic warrants liability	0	14	(24)
Change in fair value of earnout shares	(66,605)	0	0
Change in fair value of debt issuance costs and stock warrant	0	25	0
Change in fair value of redeemable convertible preferred stock tranche obligation	0	(923)	1,396
Unpaid interest expense on capital lease obligations	340	0	0
Change in Operating Assets and Liabilities:
Accounts receivable	(4,307)	(916)	(830)
Inventories	(29,519)	(3,333)	2,883
Other current assets	(3,918)	(6,445)	(6)
Other assets	(259)	44	(38)
Accounts payable	69	4,149	1,392
Accrued expenses	9,041	8,039	525
Accrued expenses – related party	(229)	96	172
Other current liabilities	498	(178)	229
Other liabilities	(1,070)	998	582
Net Cash Used in Operating Activities	(111,281)	(4,592)	(5,473)
Cash Flows from Investing Activities
Purchase of property and equipment	(10,148)	(154)	(235)
Capitalized website and internal-use software costs	(14,609)	0	0
Purchase of marketable securities	(359,896)	(1,049)	0
Proceeds from sales of marketable securities	239,931	68	0
Purchase of lease vehicles	(1,793)	(92)	(252)
Net Cash Used in Investing Activities	(146,515)	(1,227)	(487)
Cash Flows from Financing Activities
Issuance of redeemable convertible preferred stock	0	0	7,988
Payments made on long-term debt	(153)	(9)	(8)
Advance from holder of marketable securities	4,722	0	0
Repayment of advance from marketable securities	(4,722)	0	0
PIPE issuance	125,000	0	0
Merger financing	309,999	0	0
Payment made on accrued dividends	(4,853)	0	0
Payments to existing shareholders of Former CarLotz	(62,693)	0	0
Transaction costs and advisory fees	(47,579)	0	0
Payments made on cash considerations associated with stock options	(2,465)	0	0
Repayment of Paycheck Protection Program loan	(1,749)	0	0
Payments made on note payable	(3,000)	0	(418)
Payments of debt issuance costs	0	(10)	(112)
Borrowings on long-term debt	0	5,249	3,000
Payments on floor plan notes payable	(150,090)	(24,948)	(41,711)
Borrowings on floor plan notes payable	171,866	24,248	39,753
Employee stock option exercise	404	0	0
Payments made for tax on equity award transactions	(339)	0	0
Net Cash Provided by Financing Activities	334,348	4,530	8,492
Net Change in Cash and Cash Equivalents Including Restricted Cash	76,552	(1,289)	2,532
Cash and cash equivalents and restricted cash, beginning	2,813	4,102	1,570
Cash and cash equivalents and restricted cash, ending	79,365	2,813	4,102
Supplemental Disclosure of Cash Flow Information
Cash paid for interest	1,743	346	684
Supplementary Schedule of Non-cash Investing and Financing Activities:
Transfer From Property And Equipment To Inventory	0	27	53
Transfer from lease vehicles to inventory	264	217	295
Redeemable convertible preferred stock distributions accrued	0	1,884	1,579
Issuance of common stock warrants	0	15	72
KAR/AFC exercise of stock warrants	(144)	0	0
KAR/AFC conversion of notes payable	(3,625)	0	0
Convertible redeemable preferred stock tranche obligation expiration	(2,832)	0	0
Capitalized website and internal use software costs accrued	(790)	0	0
Purchase of property and equipment costs accrued	(1,034)	0	0
Purchases of property under capital lease obligation	(11,261)	1,305	0
Settlement of redeemable convertible preferred stock tranche obligation	$ 0	$ 0	$ (902)