You can see the cost of customer factoring programs increased by $0.9 million in Q1. But I would point out that we can see the cost of those programs leveling out now that interest rates have been more steady, albeit at a much higher level than several years ago. Turning now to the balance sheet. Accounts receivable were $203.9 million at the end of the quarter and inventory levels finished Q1 at $520.7 million, with both balances in line with March last year. Increases in receivable and inventory from December 2023 related to the seasonal increases in sales and preparation for Temp Control selling season. Our cash flow statement reflects cash used in operations for the first quarter of $45.7 million as compared to cash used of $20.4 million last year.
Cash used in operations last year was aided by a reduction in inventory balances that did not recur this year after we brought inventory back down to normal levels through the course of 2023. Our investing activities show an increase in capital expenditures this year of $5.7 million which includes $2.6 million of investment related to our new distribution center. Financing activities show borrowings on our revolving credit agreement of $58.7 million in the first quarter, which were used to fund operations, capital expenditures and pay $6.4 million of dividends. We also began repurchasing shares under an existing $30 million authorization from our Board, and repurchased $2.6 million of shares during the quarter. We continue to purchase shares in the second quarter.
And as we noted in our release this morning, purchased an additional $3.5 million through April 29 for a total of $6.1 million repurchased so far this year. Our net debt of $187.7 million at the end of Q1, was much lower than last year, and we finished the quarter with a leverage ratio of 1.6x and lower than last year’s ratio. Before I finish, I want to give an update on our sales and profit expectations for the full year of 2024. Regarding our top line sales, we are maintaining the expectations we laid out before and expect full year 2024 sales will show flat to low single-digit percentage growth. We’re also maintaining our expectations for adjusted EBITDA, which we expect to be in a range of 9% to 9.5%, and essentially flat for 2023. This estimate continues to include factoring expenses of $45 million to $48 million, largely flat with 2023 as we remain in a high and uncertain interest rate environment, the U.S. dollar that remains at a multiyear low against key currencies in Mexico and Poland and some additional costs related to the expansion of distribution capabilities in our new warehouse in Kansas, which we estimate $5 million to $6 million incremental cost in 2024.
In connection with our adjusted EBITDA outlook, we expect our interest expense on outstanding debt to be on average about $3 million to $4 million each quarter, and we expect our income tax rate to be 25%. Borrowings are expected to remain roughly flat from December 2023 to December 2024 as cash flows normalize. And we look to invest approximately $25 million in our new DC, and return cash to shareholders via dividends and share repurchases. Regarding operating expenses for the full year, keep in mind our operating expenses are incurred ratably across the year and do not necessarily vary with top line sales as the majority of these costs are fixed in nature. As such, we anticipate total operating expenses, inclusive of factoring will range from $76 million to $82 million for each of the last three quarters of 2024.
To quickly wrap up, we were pleased to see our sales increase in Q1 despite slightly slower preseason orders in Temp Control and to turn in results in line with our forecast, while also increasing shareholder returns through share repurchases in the quarter. Thank you for your attention. I’ll turn the call back to Eric for some final comments.
Eric Sills: Thank you, Nathan. In closing, I’d like to spend a minute on how we are thinking about the future. The aftermarket continues to be a strong and stable market. All signs suggest that after a few years of unusual demand behavior coming out of the pandemic, it has returned to its historical long-term trend of low single-digit growth, which makes sense when you consider the basic dynamics of the addressable market, where thing change very slowly, but in the right direction. The car park slowly gets larger and older, miles driven has returned to stable levels. People are keeping their cars longer, especially in light of the high cost of new vehicles. And when you put these together, they add up to slow growth. We recognize that the record inflation over these last few years have caused challenges to consumers.
And while this could dampen discretionary purchases, much of what we sell is nondiscretionary in nature. Engineered Solutions is more difficult to summarize as it is so diverse in end market customer, product and geography. But as we’ve been saying, we believe our sales trajectory will be less determined by ebbs and flows in these markets as it will be by gaining and launching new business wins and building on these wins. It’s obviously not lost on us that we have work to do to return to our historic margins, and we are focusing diligently on this. So overall, when you put it all together, the long view remains quite positive. That concludes our prepared remarks. At this point, I will turn it back over to the moderator, and we’ll open it up for questions.
Operator: [Operator Instructions] We’ll go first this morning to Scott Stember of ROTH MKM.
Scott Stember: Eric, you talked about how, I guess, the weakness that we saw in Q4 a sort of reverse and that things are back to normal yet. On the other hand, you talked about POS being a little soft. Is that more just a function of tough year-over-year comparisons? Or is there something else going on?
Eric Sills: I think that’s a fair statement, Scott, that it is more about the fact that the first quarter of 2023 was really quite strong. If you think about the POS trends coming through the fourth quarter of last year and into this year, last year, we saw a sequential erosion of that POS month-over-month. And that continued a bit into January of this year. And now we started to see a bit of a rebound. So if you look at the whole quarter this year, POS was a bit soft. But I think that it also does reflect more of that return to where we’d expect it to be.
Scott Stember: So when you say soft, are we talking flat or down slightly for the whole quarter?
Eric Sills: It moderated throughout the quarter. And overall, it was roughly in that flat. There were some periods and some customers that were a little bit up or down from that. But overall, it’s — that’s what we saw.
Scott Stember: Got it. And then on the engine solutions side, it looks like the — most of the growth came from the other segment. Is that UTV mostly, or is there something else in there? And what’s driving that?
