In the fourth quarter, we closed on the transformative acquisitions of Larry H. Miller and Total Care Auto, powered by Landcar, Kahlo Chrysler Jeep Dodge, Arapahoe Hyundai-Genesis and the Stevinson Automotive Group, representing approximately $6.6 billion in annualized revenue.
For the full year, we grew adjusted EBITDA by 94% and adjusted earnings per share by 112%.
We delivered an operating margin adjusted at 8.1%.
Our adjusted operating cash flow for 2021 was $632 million, an increase of $189 million over 2020.
Our net leverage ended this quarter at 2.7 times.
Our same-store adjusted revenue grew almost 12% last year, exceeding expectations.
Clicklane continues to deliver impressive metrics, generating over $570 million in additional revenue for three quarters in 2021.
Despite lower new vehicle levels, inventory levels, Clicklane contributed an incremental 7% to our same-store growth.
We delivered strong results, enabling us to deliver an impressive gross margin of 20.4%, an all-time record and an expansion of 370 basis points versus the fourth quarter last year.
Our teams continue to maximize productivity per employee, resulting in adjusted SG&A as a percentage of gross profit of 54.3%, a 710 basis point improvement versus prior year.
Our total revenue for the quarter was up 19% year over year and total gross profit was up 46%.
We improved our adjusted operating margins for the quarter from 6% in 2020 to 8.9% in 2021, and we'll continue to optimize our portfolio in the future.
Our new average gross profit per vehicle was $6,335, up $3,441 or 119% from the prior-year period.
At the end of December, our total new vehicle inventory was $207 million and our day supply was at eight days, down 32 days from the prior year.
Our used retail volume increased 15%, while gross margin was 8.2%, representing an average gross profit per vehicle of $2,623.
As a result of our performance, our retail gross profit was up 64%.
Our total used vehicle inventory ended the quarter at $402 million, which represents a 34-day supply, up three days from the prior year.
Our used to new ratio for the quarter was 109%.
Our strong, consistent and sustainable growth in F&I delivered an increase of $213 to $1,961 per vehicle retailed from the prior-year quarter.
In the fourth quarter, our front-end yield per vehicle increased $2,169 per vehicle to an all-time record of $6,362.
Our parts and service revenue increased 13% in the quarter.
The warranty revenue dropped 19%.
Our customer pay revenue continues its healthy recovery, posting a 17% growth.
We achieved over 149,000 online service appointments, an all-time record and a 16% increase over the prior-year quarter.
We sold over 5,000 vehicles through Clicklane in Q4, of which 47% of them were new vehicles and 53% used.
91% of our transactions this quarter were with customers that were new to Asbury's dealership network.
Average transaction time continues to be consistent with previous quarter, eight minutes for cash deals and 14 minutes for finance deals.
Total variable front-end yield of $4,298 and F&I front-end yield of $1,846.
80% of consumers seeking financing received instant approval, while an additional 10% require some off-line assistance.
90% of those that applied were approved for financing.
43% of Clicklane sales had trade-ins with 78% of such trades reconditioned in retail to consumers with a total front-end yield of $4,490.
And 92% of our Clicklane deliveries are within a 50-mile radius of our stores, thus allowing us the opportunity to retain our new customers in our parts and service departments.
During our first few months after launching Clicklane, approximately 60% of our sales were new vehicles.
Overall, compared to the fourth quarter of last year, our actions to manage gross profit and control expenses resulted in a fourth quarter adjusted operating margin of 8.9%, an increase of 290 basis points above the same period last year and an all-time record.
Adjusted net income increased 89% to $163 million, and adjusted earnings per share increased 68% to $7.46.
Net income for the fourth quarter of 2021 was adjusted for acquisition expenses and acquisition-related financing expenses of $289 million or $1.02 per diluted share.
Net income for the fourth quarter of 2020 was adjusted for a gain on dealership divestiture of $3.9 million or $0.15 per diluted share.
If the financing had closed simultaneously with the Larry H. Miller acquisition, our adjusted earnings per share for the fourth quarter would have been positively impacted by $0.87 as a result of lower interest expense and fewer outstanding shares.
Adjusted operating margin was 8.1%, an increase of 240 basis points at an all-time record.
Adjusted net income increased 120% to $549 million and adjusted earnings per share increased 112% to $27.29.
Our effective tax rate was 23.7% for 2021 compared to 24.8% in 2020.
This quarter, we acquired $6.6 billion in annualized revenue.
In order to finance the acquisitions, we completed debt and equity offerings totaling approximately $2.1 billion, a syndicated mortgage facility of approximately $700 million and borrowed under our upsized syndicated credit facility.
In addition, we spent approximately $34 million of capital expenditures in the quarter.
We generated $632 million of adjusted operating cash flow for the year.
Our balance sheet remains healthy as we ended the quarter with approximately $437 million of liquidity, comprised of cash, excluding cash to Total Care Auto, floorplan offset accounts and availability on both our used line and revolving credit facility.
Also at the end of the quarter, our net leverage ratio stood at 2.7 times, below our targeted net leverage of three times.
As David stated earlier, today, we announced that our board has approved an increase to our share repurchase authorization by $100 million to $200 million.
For 2022, we are planning for a tax rate of approximately 25% to 26% and capex of approximately $150 million.
As a result, we are planning our business for a SAAR of 15.5 million to 16 million units and vehicle margins consistent with 2021.

Summary:
Our total revenue for the quarter was up 19% year over year and total gross profit was up 46%.
We sold over 5,000 vehicles through Clicklane in Q4, of which 47% of them were new vehicles and 53% used.
Adjusted net income increased 89% to $163 million, and adjusted earnings per share increased 68% to $7.46.
As David stated earlier, today, we announced that our board has approved an increase to our share repurchase authorization by $100 million to $200 million.