Don't know which way you head to the airport, but, if it's 476S to 95N, Colonial Airport Park is a very quick easy off exit at Essington (don't remember the exit number, but, I believe the route is 412S). Exit south on 412 from 95N to the first traffic light (very short distance) make a left onto Industrial HIghway ....Colonial is on the right approximately a mile. We've been using them for about five years .....several times a year. They always have a coupon for $1.00 per day discount on their website. I think the current price (with coupon, including taxes) is about $8.00 per day. Secure lot, well lit, open 24 hours a day. The shuttle runs continuously thru the lot and picks up/drops off right at your car.
Usually by the time we have our bags unloaded from the trunk the shuttle is there waiting for us. On your return to the airport simply call their toll free number (remember to either take the phone number with you or pick up one of their business cards on the shuttle and write which section you're parked).
The longest we've waited at bag claim to be picked up was about 10 minutes.
I know others have used valet services for their car, but, I just don't feel comfortable with that. It's one thing to park your car in a secure lot for a week.....another to have a valet service drop you off in your vehicle and have your car and keys for the week.