Two firms can quote nearly identical figures and mean very different amounts of work. The number is only meaningful once you know which stage of the case it ends at.
Some agreements cover everything through arraignment and early pretrial hearings, then reprice. Find the sentence that names the stopping point before you compare quotes.
A trial fee charged per day and a single flat trial fee produce very different totals in a case that runs longer than expected. Ask which structure applies and what a typical DUI trial length has been.

Challenges to the stop, the breath test procedure, or field sobriety evidence are the most commonly excluded item in a flat fee. Ask specifically which motions are inside the quote.
A retainer agreement for a drunk driving charge in Washington almost never quotes one number for one thing. It quotes one number for a defined stage of work, and the stages that follow have their own prices, their own triggers, and sometimes their own separate signature line. A careful reader treats the headline figure as the answer to a question the agreement has already narrowed, and spends the consultation working out how narrow. The difference between two firms quoting similar amounts is usually not the amount. It is where each one draws the line.
Set two King County retainers side by side and the first divergence is usually the definition of the covered phase. One agreement may cover everything through arraignment, pretrial hearings, discovery review, negotiation with the prosecutor, and the resolution of the case short of trial. Another covers the same ground but stops at the filing of a suppression motion, treating the motion, the hearing, and the briefing as a separate engagement with a separate fee. Both are legitimate ways to price the work. Only one tells you, on the first page, what a contested case will cost.
The practical test is to read backward from trial. Ask what the agreement says happens if the case is set for trial, and then ask what happens if trial is continued twice, which is common. Some agreements charge a trial fee per day, some charge a single flat trial fee, some require a new retainer entirely once a trial date is confirmed. A per-day structure and a flat structure can produce very different totals in a case that runs three days rather than one, and the agreement rarely says which is more likely.
Drunk driving cases turn on pretrial litigation more than most misdemeanors, which is why motion practice is the most common exclusion worth finding. A motion to suppress the stop, a challenge to the breath test procedure, a request to exclude field sobriety evidence: each of these may be inside the quoted fee, outside it, or inside it up to a stated number of hours. The National Highway Traffic Safety Administration oversees the federal impaired driving programs and the standardized testing protocols that much of this litigation examines, and a defense that engages seriously with those protocols takes real hours. Ask which motions the quote anticipates, and which ones would generate a new invoice.
The second layer is what a motion drags with it. Subpoenas cost money to issue and serve. Transcripts of an earlier hearing cost money to order. If a state toxicologist or an arresting officer has to be brought in for testimony, someone pays the witness fee and the mileage. These items are usually described as costs rather than fees, which is why they sit in a different paragraph, often further down, and why a reader scanning for dollar signs can miss them entirely.
An independent expert on breath testing, blood analysis, or retrograde extrapolation is almost always outside a flat fee, and honest agreements say so plainly. The relevant question is not whether the expert is included, because expert time is rarely predictable enough to bundle. It is who decides that an expert is needed, what the attorney estimates such a review typically runs, and whether you approve the engagement before it happens. An agreement that requires written authorization before any cost above a stated threshold is doing the reader a favor, because it converts a surprise into a decision.
Records requests belong in the same paragraph. Maintenance logs for the breath instrument, calibration records, dispatch audio, body camera footage, and the officer's training file all arrive through requests that carry duplication charges. Individually these are small. Together, across a contested case, they are the difference between an estimate that held and one that did not, and they are worth asking about by name rather than as a category.
Bring three questions to the free consultation. What does this fee cover if the case resolves at the first pretrial hearing, and what does it cover if it does not. Which specific motions would trigger an additional fee, and what has that fee typically been. What happens to the money already paid if the case ends early, or if you decide partway through to hire someone else. A firm that answers in specifics, and points to the paragraph where each answer lives, has given you a document you can actually plan around.
The agreement you want is not the cheapest one on the page. It is the one whose scope you can describe accurately to someone else after reading it once.