Tamaulipas → Coahuila · Autopista 40D Reynosa-Monterrey
On heavy-rain or dense-fog days the Reynosa, Tamaulipas, to Saltillo, Coahuila, leg routinely demands well more than the 3h 56m estimated: Autopista 40D Reynosa-Monterrey carries known hydroplaning hot spots and reduced-visibility corridors that justify dropping to 35 mph through a few short stretches. The outbound run covers 354 km (220 miles) over varied topography between Reynosa (the frontera con McAllen y polo maquilador del noreste fronterizo) and Saltillo (the capital coahuilense y centro de la industria automotriz Chrysler), demanding sharper attention on mountain descents and shoulder-less curves. Before pulling out, check brake-pad wear, tire tread depth, and washer-fluid level in the reservoir. Fuel spend holds near MXN 713.90 for the 29.5 liters (7.8 gallons) consumed. Even in adverse conditions, the flat tariff of MXN 6.50/km guarantees the standard outbound payout of MXN 2301.00 — log any incidental costs (extra toll, mandatory meal, emergency lodging) in a separate field on the Clara receipt. For the Canadian professional driving the 354 km between Reynosa and Saltillo, reimbursement of MXN 2301.00 stays excluded from T4 employment income provided the per-kilometre rate matches the CRA's reasonable allowance benchmark for the province. Canadian employers typically reimburse at the CRA reasonable per-kilometre rate (61¢ for the first 5,000 km in 2024) so the payment is excluded from T4 employment income. Keep the GST/HST-compliant fuel receipt from any NRCan-tracked retail network station used during the trip — Canada Revenue Agency (CRA) auditors regularly verify fuel-receipt GST/HST when reviewing T2200 declarations of conditions of employment. The Reynosa→Saltillo mileage must be logged with date, business purpose, opening and closing odometer readings inside the corporate expense system before month-end close to remain deductible.