SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) obligation	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Revenue, Major Customer [Line Items]
Number of performance obligations | obligation			2
Basic vehicle warranty term			4 years
Revenue	$ 137,814	$ 195,457	$ 438,120	$ 350,468
Vehicle Sales With RVG
Revenue, Major Customer [Line Items]
Revenue	56,500	$ 10,100	112,000	$ 10,100
Vehicle Sales With OTA and Remarketing | Other Current Liabilities
Revenue, Major Customer [Line Items]
Deferred revenue	6,700		6,700		$ 4,000
Vehicle Sales With OTA and Remarketing | Other Noncurrent Liabilities
Revenue, Major Customer [Line Items]
Deferred revenue	$ 18,200		$ 18,200		$ 11,400