Picture it: a back seat full of contented kids enjoying a long drive . . . or parents chatting in a restaurant while their kids wait quietly for their meals. A few carefully chosen mobile toys could turn these travel-time fantasies into reality.

Here are some kid-tested ideas. Age recommendations are approximate, and prices will vary. Age 6 months to 5 years

Busy Drive (Child Guidance by Gabriel, $11) A lap-size dashboard with an ignition, clock, windshield wiper and steering wheel.

Security Bunny (Fisher-Price, $6.75), a soft, machine-washable blanket with a puppet-like head, provides company as well as comfort.

Stay Put Suction Cup Rattle (Playskool, $3). Adheres to any smooth surface and serves triple duty as rattle, teether and toy.

Tumble Turvey Triangle (Mattel, $7.50). The encased clown's face changes expression with every turn. Ages 3 to 7

Pop-o-matic bingo (Gabriel, $8. Offers children the excitement of competition and parents the joy of no loose parts.

The Woodsey's Airport (Fisher-Price, $11). This self-contained playset includes a storybook lauding the fun of flying, plus a soft hangar containing a colorful, foam-filled plane and finger puppet.

Li'l Boss (Child Guidance by Gabriel, $14). For aspiring executives to emulate Mom or Dad, this tote-along brief case is filled with reusable note pad, switchboard, typewriter, clock, phone and a secret compartment for trip memorabilia.

Dolly Pops Dollhouse (Knockerbocker, $18). A small, plastic house with furniture and family that snap into place during play and store inside.

Gre-Gory Big Bad Vampire Bat (Matell, $11). For courageous children mad for monsters, this soft, vinyl toy has flappable wings, bendable teeth and (when his back is pressed) red liquid that surges through his see-through belly. Ages 6 to 12

Plastic Sliding Puzzle (American Publishing Corporation, $2). Pieces are mobile but intact.

Darci Fashion Case (Kenner, $9.95). For doll-fanciers, there is space for Darci or her friend, Erica (Kenner $6.50), along with travel necessities.

Firestar I (Fisher-Price, $4.50). Future astronauts can escape into space on a sleek rocket sled with a life-support cable for the accompanying pilot.

Krusher (Mattel, $14). For releasing pent-up energies on a long drive, this monster can be scrunched into a blob, squeezed until he "breathes" and flexes or allowed to "grow" back into his human shape.

View-Master (3-D) Viewer (GAF, $2.95). This time-honored device has entertained many a child back-seat driver. Three-reel Packets ($2.75) are available on subjects ranging from nature and comic heroes to movies and scenic attractions. The new Collector's Library Chest ($4.25) will hold the viewer and up to 25 packets.

Tiny toys that fit into your poctet or purse can be real life savers during travel. Here are a few 1980 examples:

Sweet Treats Ice Cream Bars (Mattel $4.50, age 3 and up). Each dripless bar opens into a miniature beauty salon, complete with 2-inch doll, chair and comb.

Acrobot (TOMY, $1.50, age 3 and up). This wind-up robot flips and falls, but always ends up on his feet.

Pocket Boggle (Parker Brothers, $4.50, age 8 and up). Because letter strips are used instead of cubes, this popular word game can travel anyway and remain intact.

Stomper 4X4s (Schaper, $4.95, ages 4 and up). These small, 4-wheel-drive cars will climb most obstacles in front of them.

Sesame Street Squeak and Shakies (gabriel, $3, birth to 2 years). Drool-resistant and soft, these Sesame Street pals entertain baby with various sounds when squeezed or shaken.

Kid-a-Long Kids (TOMY $1.25, ages 3 and up). Whether riding a pony, wagon, tricycle, skateboard or roller-skates, these cute kids need only winding to get into action.

The Muppet Show Players (Fisher-Price $3, ages 4 and up). This set of colorfully detailed finger puppets includes Miss Piggy, Kermit, Fuzzie and Rowlf.

Pocket Erector (Gabriel, $2, age 6 and up). A miniature construction set, complete with plans to build a variety of models.

There are also many no-cost, have-on-hand possibilities such as:

Fabric scraps of different textures that provide babies and toddlers with the tactile stimulation they thrive on;

Paper bags that make super puppets for preschoolers;

One deck of cards that offers a multitude of games for all ages;

The ever dependable paper and pencil, or crayon, which can illustrate your trip.