Method:

• In 1-quart saucepan, heat oil over medium-high heat. Cook onion and garlic in oil, stirring frequently, until onion is tender; remove from heat. Stir in chili sauce, salt, pepper and beer.
• Place beef in shallow glass or plastic dish or resealable food-storage plastic bag. Pour beer mixture over beef; turn beef to coat with marinade. Cover dish or seal bag and refrigerate, turning beef occasionally, at least 8 hours but no longer than 24 hours.
• Cover wood chips with water; soak 30 minutes. If using charcoal grill, place drip pan directly under grilling area, and arrange coals around edge of firebox. Heat coals or gas grill for indirect heat.
• Remove beef from marinade; reserve marinade. Insert spit rod lengthwise through center of beef; hold firmly in place with adjustable holding forks. Insert barbecue meat thermometer so tip is near center of beef but not touching spit rod. Drain wood chips. Add about 1/2 cup wood chips to medium-low coals or lava rock.
• Cover and grill beef on rotisserie over drip pan and 4 inches from medium-low heat about 2 hours for medium doneness (160F), brushing occasionally with marinade and adding 1/2 cup wood chips to coals or rock every 30 minutes. Remove spit rod, holding forks and thermometer. Discard any remaining marinade. Cover beef with foil and let stand 15 minutes before slicing.