Just because you can't afford to buy a new car doesn't mean that you're doomed to drive an old school clunker for the rest of your life. In fact, an entire industry exists to supply drivers like yourself with an array of aftermarket gadgets, gizmos, and doohickeys that'll make your old car feel new again.

While MTV's Pimp My Ride would lead some to believe that only a fish tank in the trunk will do the trick, here are some more practical and affordable options to bring your car up to speed. Before signing a lease on a new car, consider these automotive upgrades that cost less than $500.

Exterior

Your car's appearance says a lot about who you are. And because first impressions count, it's wise to keep your car looking its best. Provided that your vehicle's body and paint are in good condition, that's not hard to do. Check out these affordable options: 

Lights - A simple, yet often overlooked modification that can brighten your car's appearance is replacing its stock front lights with a set of chrome or black housing projector headlamps. These lights provide a powerful beam of light that's more concentrated than stock lamps, so they shine further and more brightly than that of most cars. Matched with a sharp set of LED tail lights, your car will look both modern and elegant. Depending on what you drive, expect to pay between $200 to $300 for each set.

Wheels - It's no secret that a decent pair of rims can set your car off right. And although chrome spinners look ridiculous and 22-inchers can literally be a pain in the butt to drive on, there are a lot of modest, yet attractive wheels you can buy on a budget. Brand new, expect to pay about $125 per rim for something very simple. Keep in mind that tires and installation will add to the cost.

Window Tinting - Not only does window tinting look cool, but it'll help keep you feeling that way during the dog days of summer. What's more, it provides loads of privacy, deflects harmful UV rays, can prevent your upholstery from cracking, and will even hold your windshield together in the event of a glass-shattering crash. And because it's available in a wide variety of shades and colors, drivers are afforded a degree of customization too. The price depends on your car's make and model as well as the type of tinting you chose, but you can expect to pay a few hundred dollars. The truly brave can buy a kit for under a hundred and attempt to install it themselves -- though ugly bubbles are likely to result.

Interior

If you use your car for daily commutes, chances are that your upholstery is worn. With kids, dogs, spills and tears, it's a wonder you've got any more of that bland, blue-grey vinyl left on your seats at all. But there's a lot you can do to make your interior pop, even on a limited budget. Consider these three affordable options:

Dash Kit - Most affordable cars come covered in plastic moldings and hard-touch surfaces -- which, over time, get faded and warped by the sun. With dashboard refinishing kits you can upgrade to the luxury look of wood grain or sporty styling of brushed aluminum, and even do it yourself. Available in a wide range of colors, grains, and materials, these kits feature pre-cut pieces that stick right over your old dash. However, depending on your car and the kit you chose, the price can vary. Expect to pay somewhere in the range of $200 -- without professional installation. 

Pampered Seating - With today's technology, it no longer matters if your seats do nothing other than manually adjust back and forth. For a few hundred dollars professional auto-trimmers can install seat massagers, heaters, or even gel cushioning in your driver's seat. While you're at it, have them reinforce your foam rubber too. After tens of thousands of miles under your kiester, your foam probably feels a lot less supportive than it did when you first bought your car. 

Seat Covers - A significant way to revitalize your interior is with high-quality vinyl, cloth, or even leather seat covers, which can be custom ordered in a variety of grains and color-schemes. For an extra cost, some manufacturers will even allow you to personalize your covers with an embroidered symbol. However, not all suppliers sell directly to consumers, so you may need to visit a local auto upholstery shop to place an order. While there, consider having them install it too -- as only a professional can get that snug, wrinkle-free look. Keep in mind that the cost of new seat covers can range from a few hundred to over a thousand dollars, depending on what type of car you drive, the material and pattern, and who does the installing.

Gadgetry

Even if your car didn't come with a lot of convenience features you can still drive a car like KITT by updating your interior with modern, yet affordable, gadgetry. Just be sure to install an alarm system too, as these gizmos will significantly increase the desirability of your ride:

GPS Navigation - Long gone are the days when taping MapQuest printouts to your steering wheel seemed like a good idea. Portable navigation devices will get you where you need to go and more. In addition to accurate directions, many provide drivers with such cool features as real-time traffic reports, local news and movie listings. Some even double as MP3 players. Prices vary by brand and features, but expect to pay somewhere in the range of $200 to $500 for a good system. Research the best inexpensive and mid-range GPS systems with US News' GPS Reviews.  

Video Screen - You don't need to be an aspiring hip-hop mogul to have TV screens installed in your headrests. Many parents enjoy them simply because it gives their kids something to do other than play Punch Buggy in the backseat. Flip-down LCD monitors with attached DVD players are also available, and can easily be attached to the inside roof of your car. While prices start around a few hundred dollars, keep in mind that having it installed will cost extra.  

iPod-Ready Stereo System - In this digital age, there's no longer a need to line your sun visors with CD sleeves and hide an entire album of discs under your seat. By upgrading to a stereo system that's compatible with your MP3 player, you can just plug an iPod into the unit and have access to your entire music collection within seconds. What's more, many of these systems are even satellite radio- and Bluetooth-ready. Prices range between $100 to a few thousand, so opt for a mid-range system and you'll have enough money left over to upgrade your speakers too.